There is now a reason for the sudden appearance of this issue. It is affecting other manufacturer’s MQA streams from Tidal too. See link.
The reason behind this is that Tidal have unilaterally changed how they are identifying Tidal Master files. So the cause does not lie with Mosaic but that the change by Tidal has resulted in this outcome.
So either Tidal should revert to the previous situation or there could be a hiatus for a period while streamer manufacturers revise their software and issue updates. I would guess that for us folks the latter would logically be rolled in with the anticipated Mosaic v. 1.1.2 revision and if so I would not anticipate a particularly swift conclusion, at least from past experience.