The check being discussed here is checking how much memory is free on the OS, not how much memory Ghost is using. It’s possible something else besides Ghost is using more memory. Use htop or a similar tool to review which processes are consuming your memory.
Thanks. I actually did look at this, and it’s mysql/mysqld hogging memory. For me, adding a 2GB swap solved the problem. I’m really just curious if anyone knows why mysql 8 & ubuntu 20/22 have this issue in the first place (the issue being far higher memory usage from mysql).
There are some tips here on tuning MySQL to reduce the memory use. I have not tried them myself.