You could try increasing cma size further to 448 or 512 (the latter is used on RPi4 by default, but it could be problematic with only 1GB RAM).
It might also be worth to try a full clean installation on a separate SD card (without any further addons, skins etc) - it could also be related to some addon or setting you changed.
We'll need a full pastecrash log to give further advice (non-debug log might already help and cut size down, but debug log would be preferred of course).
so long,
Hias