Something is definitely wrong with your latest updates. Validator constantly stopping once it become active / selected afte 5 mins it just unexpectably stops for no reason. I can't find anything in logs related to my problem and they look really useless, the only one row in error.log is this one
{"level":"error","message":"Unable to fetch node info: Error: connect ECONNREFUSED 127.0.0.1:9001","service":"node"}
GUI Version 1.2.1
Validator Version 1.15.4
Here's the screenshot from my Contabo VPS server monitoring