samsung washing machine WF90F5E5U4W stops working mid-cycle

I have a washing machine that should be a model WF90F5E5U4W, but I bought it second hand, and I think there are some parts from a different machine as well (perhaps the electronics). I don't think the parts are wildly different, I suspect it's simply the same kind of machine with a different capacity.

It will stop running in the middle of a wash cycle, none of the buttons work, and the display is off. After a few minutes or sometimes a few hours it will continue where it left off (and maybe turn off a few more times). I have the feeling that some cycles are less likely to cause problems than others, but that might be wrong (I had the feeling that cycles without heat caused fewer problems).

I took it apart, couldn't see anything wrong with the electronics, motor or anything else. I replaced the thermistor, but that didn't solve the problem unfortunately.

Is there anything else I can try to do?