I have the same problem with tidal on WiFi and wire too. I have fiber internet 1 gbps and WiFi 7 router so on WiFi I get 1000. - 900 mbps, so my internet is not a problem. I think that start happens after last firmware update. I do factory reset and there is no difference. That happens only on max audio quality.
When that happened my router show that WiiM amp use only 0,3-0,5 mbps, that is so small amount of transfer to play high quality music.
When all is ok router show much more data traffic like 3-6 mbps depends on audio file quality.
In my opinion problem is with network connection on WiiM amp device.
When I play music on my iPhone is no problem with this so my internet connection is no a problem, other devices working normal, only WiiM amp device have problem.
Please fix it!