There is a bug in WSL2 that causes the memory consumption of the vmmem process to not to be released. Right now, the version of WSL2 and windows i´m using is Windows 10 19043.1110 (21H1) and it´s still present.
This is what you can see when the error happens:
1) You have your WSL2 images stopped:
2) There is a lot of memory ussage from the vmmem process:
The solution for this is to simply stop the vmmem process:
Et voila :)