Rough cold start persists after plugs and 2 ignition coil replacements (2020 Kia Forte, 91k miles)
Issue started Saturday with a very rough cold start, severe shaking, and a check engine light. Shop pulled P0304 (cylinder 4 misfire). They replaced all 4 spark plugs and ignition coil #4.
Two days later (Monday), another rough cold start and check engine light. Shop pulled P0301 (cylinder 1 misfire). They said they moved coil #1 to another cylinder and the misfire followed the coil, so coil #1 was replaced.
Today (Tuesday), on a cold start, the engine is still shaking noticeably and the check engine light came back on again. The shaking is somewhat less severe than before but still significant. Once the engine warms up, the idle improves considerably, but the check engine light remains on.
I do not yet know the current code.
Video attached is from a cold start.
At this point, does this still sound like multiple ignition coils failing in succession, or should I be looking at something else such as an injector, vacuum leak, wiring issue, carbon buildup, intake issue, or compression issue?
Any thoughts on what should be tested next would be appreciated.