Cubase project lags, MIDI and Audio tracks then output huge noise which breaks the track

Currently using Cubase Pro 10.5.

I haven’t had it during editing, only playback, whether that’s a coincidence or not, I don’t know.
I will play through a section of music when suddenly the program has a little lag spike (things stop moving, tracks freeze etc.) and when the software is responding again a track will output a huge wall of noise, not related to any information in the project.

It breaks the track as well. On the current project it happened on, the MIDI channel it affected showed that the channel was outputting max volume (and that showed in the Stereo Out too). However, there was no audio coming from my monitors, and other channels were operating as normal. I’ve reset my MIDI, I’ve reloaded the VST, checked Mute and Solos etc. and all looks fine.
I have to reset Cubase entirely, which when using East West libraries, it’s a pain, to say the least.

I’ve never had this issue before, not even the lag, and now it’s affecting all my projects.

Any help to make sure everything is running smooth and I’m not being a numpty would be great!