This was a post from Rugby a couple of days ago.
RugbyDaniel BeyerCommunity: Moderator
The quality of Tidal’s content, non-MQA, went downhill last Oct. Not sure what it was, but, it is extremely noticeable. So much so, that I actively choose the Qobuz CD version over the Tidal CD version every time now, and again, nothing to do with MQA.
Make sure to check whether Tidal and Qobuz sound the same on your system with a range of identical non-MQA CDs before assuming differences are due to MQA or PCM. Especially timbral differences like bass, which give a darker sound.