First picture looks like it could be woodlouse.
They come out when the lights are off and eat the plants if there is no other food source.(mulch/straw/rice hulls)
You may have brought them in with your soil…
If you come in when the lights are off and shine a torch over your plants you may see them.
Sounds mad, but it took me about a week to work out it was those fuckers!!
Also check in your saucers as they hide there too.
Add mulch to your pots.