Do you think that's why the problem?
Maybe, it is just my guess but most of what I heard if they bought a different PSU model they experience different issues not the same as yours but I think related.
Since you said the hashrate goes down what hashrate does it drop?
If it drops 2 to 5th/s I think it's normal to see it will automatically drop the hashrate due to abnormal status.
Can you try to force your miner to performance mode? Based on your logs it's running in normal mode let's see if there is any changes.