Thanks for the advice, I'll try it out...
I have previously been concerned about memory usage. I used to have a Windows VM also, but I have replaced that with an Ubuntu one to lower memory consumption.
Since I did that the "Memory usage", shown in the dashboard, have been bellow 50% whenever I checked it, so I'm not quite sure that the issue lies here. However, it's worth a test
I have also set the "Fix Common Problems" plugin to "Troubleshooting" mode, so if it happens again, then maybe I'll have some more info logged