u/Beneficial_Desk_3075

TL;DR: I have Frontier 1 Gig fiber, but because my house was not wired for Ethernet, the connection travels from the garage ONT through two Frontier FCA252 MoCA adapters and the home’s coax wiring before reaching my eero Pro 7.

For months, the whole network has randomly entered a severely degraded state with latency reaching 1,000–2,400+ ms and occasional packet loss, even though my local connection to the eero stays around 4 ms. The issue affects multiple computers and phones, so it is not limited to one Wi-Fi device.

I discovered and removed an old four-way coax splitter that was incorrectly connected OUT-to-OUT, which noticeably improved speeds, but the severe latency eventually returned. Restarting the eero did not help, and the problem remained overnight. Power-cycling only the older garage-side FCA252 immediately restored normal latency.

Frontier support saw normal speeds after the connection recovered, said everything looked fine, tried to sell me a $10/month device-support service, and warned that a technician could cost $150. After a long chat, they finally agreed to ship another FCA252.

I’m now testing whether the older garage MoCA adapter, its power supply, Ethernet cable, or the ONT Ethernet handoff is causing the intermittent issue. I’m posting this both to document the experience and to see whether anyone else has dealt with similar Frontier/Verizon-era MoCA problems.

I wanted to share my experience troubleshooting a really frustrating intermittent issue with my Frontier 1 Gig fiber service. I’m also hoping somebody with more experience with Frontier’s ONTs and FCA252 MoCA adapters can tell me whether my diagnosis makes sense.

For context, my house was built in the early 2000s and was not originally wired with Ethernet. The Frontier fiber terminates at an ONT in the garage. From there, the connection travels like this:

Fiber → ONT → Ethernet → Frontier FCA252 MoCA adapter in the garage → existing coax through the house → second FCA252 in the family room → Ethernet → eero Pro 7 gateway.

When the connection is working normally, the eero reports around 950–980 Mbps in both directions. Devices near the router can also get close to gigabit speeds.

The problem is that, randomly, the entire internet connection will enter a severely degraded state. Websites barely load, Teams calls become unusable, and multiple devices are affected at the same time. Restarting things usually makes it work normally again, which made the problem extremely difficult to explain to support.

I initially thought it was a Wi-Fi issue. I tried a lot:

• Updated the Intel AX210 Wi-Fi and Bluetooth drivers
• Eventually replaced the AX210 with a TP-Link Wi-Fi 7 PCIe card
• Tested WPA2, WPA3, MLO, SQM and client steering
• Moved the eero Pro 7 out of a recessed wooden entertainment center and closer to the hallway
• Tested the eero 6 Extender
• Ran continuous pings to the router, Frontier’s first hop and 1.1.1.1
• Generated Windows WLAN reports
• Replaced the family-room FCA252 after Frontier shipped me another one

Some of those changes genuinely improved my local Wi-Fi, but the major intermittent problem still returned.

I also discovered that the coax path in the family room was going through a very old four-way splitter. Even worse, the MoCA signal was connected from one OUT port to another OUT port, while the splitter’s IN port was unused.

I removed the splitter and extra coax jumper completely and connected the house coax directly into the family-room FCA252. That made an immediate improvement. For the first time, I saw nearly 1,000 Mbps over Wi-Fi near the relocated eero.

However, the severe latency eventually returned.

During the latest failure, I recorded:

• Local eero gateway: 4 ms average, 7 ms maximum, 0% loss
• First Frontier hop: 296 ms average, 803 ms maximum
• Cloudflare DNS (1.1.1.1): 295 ms average, 1,396 ms maximum
• During another test, 1.1.1.1 showed 5% packet loss, 932 ms average latency and a 2,412 ms maximum

Traceroute showed the latency beginning immediately after my local gateway:

1. Local eero gateway — normal
2. First Frontier hop — hundreds of milliseconds
3. Later Frontier hops — also extremely inconsistent

My desktop, work laptop and iPhone were all affected, while the local connection to the eero remained healthy. The eero’s built-in speed test could still show over 900 Mbps, so this was not simply a permanent low-speed issue.

I restarted only the eero gateway. It did not fix the latency.

I then left everything untouched overnight. The problem was still present the following morning.

That morning, I unplugged only the older FCA252 located inside the garage ONT enclosure. I left it unplugged for about two minutes and then powered it back on.

I did not restart:

• The ONT
• The newer family-room FCA252
• The eero
• My computer

Immediately after power-cycling only the garage FCA252, latency returned to normal.

That seems to narrow the suspect area to:

• The older garage FCA252 itself
• Its power adapter
• The short Ethernet cable between the ONT and FCA252
• The garage-side coax connection
• The ONT’s Ethernet port or handoff

I then contacted Frontier support and supplied all of these measurements. Unfortunately, because their remote test showed approximately 977/968 Mbps after the connection was already working again, they repeatedly told me that everything looked fine.

They also:

• Focused on the age of my router even though it is a relatively new Frontier-provided eero Pro 7
• Asked whether the FCA252 power adapter had visible damage
• Offered me a $10/month “Premium Tech Pro” service for my connected devices
• Said a technician could cost $150 because the line test currently passed
• Told me to monitor it for another 48 hours

The frustrating part is that this was never just a complaint about a weak Wi-Fi signal or not receiving gigabit speeds. It is an intermittent equipment or WAN-path problem that disappears after the suspected equipment is restarted.

After a long chat, Frontier did agree to ship another FCA252 adapter. I plan to replace only the garage-side unit, its power supply and cable so I can test it as a controlled variable.

I’m not posting this just to complain. I’m posting because other people may have older Frontier or Verizon-era fiber installations that use coax and MoCA rather than direct Ethernet. If you are experiencing random high latency that temporarily disappears after rebooting equipment, inspect the entire path especially old splitters, unnecessary coax junctions and the MoCA adapters themselves.

My questions:

1. Has anyone experienced an FCA252 that remains linked but begins producing extreme latency until it is rebooted?
2. Could a failing power adapter cause this even if the indicator lights remain normal?
3. Could the ONT Ethernet handoff be entering a bad state that gets cleared when the FCA252 is unplugged?
4. Is there any way to view MoCA PHY rates, error counts or signal levels on Frontier’s FCA252 adapters?
5. Would you push Frontier for an ONT replacement if the issue returns after replacing both FCA252 adapters?

I’ll update this post after testing the new garage adapter.