Lineage OS

I'm using lineage for some years now, with a longer break between 19 and 20. Stayed with 19 for a long time. Everything on a Moto G7 Plus. No problems until I smashed the phone. Got two new used ones and installed 20. Both showing strange camera ... lag? Even more strange, this applies to all FOSS camera apps I've tried. Feels like the OS runs into super high CPU load and thus significant lag when using the camera app. That applied to both new phones. Can someone push me into the right direction? Thanks a lot.