thats a known “issue” and there are topics with discussions about that..
One example where I think it summarize it good:
( the other existing topics you can find with search function )
Join into and you find out , that currently LOD setting needs changed so that it match with your system. There are also other alternatives mentioned where you can have PG still enabled ( removal of 3d files ), but see existing topics.
PS: if you want to use memory cleaners, be carefull, this can cause crashs and not recommendation from my side. Simple ensure a correct pagefile setting, in special with ‘only’ 16gb RAM.