

First time isopod owner, lost a few isopods (Dairy Cow)
Hey all! I’m relatively new to the hobby, and have had 3-4 adult isopods in my tank pass since I got them in early June, however I also have found many babies, and am just looking to get opinions on if people think it was probably just their time or if my husbandry could use some work.
My substrate mix is a few different reputable brands mixed together with magnolia leaves crushed, as well as a touch of limestone and crushed, baked eggshell. The youngins seem to enjoy burrowing in the leafier layer.
I mist lightly every other day, with a big mist once a week as the terrarium is a bit more ventilated than I’d like, and I try to keep the soil moist, leaving a dryer corner.
I looked into safe plants for them, all I’ve got is a fern that died, a plant I don’t currently remember the name of, and mosses.
There are multiple cork wood hides for them, and a few rocks I scrubbed with vinegar and rinses aggressively before introducing.
They get offered repashy bug food every once in a while, but as they’re new to this particular enclosure they don’t always find it or are interested.
The springtails thrive, when I move the sphagnum hydration spot they are doing great, and I have quite a few babies, but they aren’t super active. I have not found any dead babies, but I didn’t look super hard in the interest of not bothering them too much.
Is there any first time mistakes I’m obviously making? Or is it most likely that the adults I received from the seller were simply near their time?
Thanks for any advice!