Forgive me if this is old hat to you all, but I came across a problem with getting MQA from my Tidal HiFi account. I had the right account type and I was listening to Masters but there was no blue MQA light. After much faffing about checking connections and settings for my Explorer2 I discovered that, on my computer, I had not given Tidal exclusive use of my Meridian USB DAC (as the Explorer is designated: the DAC was set as the audio output for Tidal, but not exclusively). Once set correctly all was fine. This may be a peculiarity with my Lenovo computer and its Lenovo HD Audio manager but I thought I should share it.

Cinema: 861v8, ID40,UHD722,800v4,DSP5200SE(2+C), DSP3300(4),DSW,+ various recorders and streamers.
TV+Music: MS200(x2),Explorer2,QNAP TS253A,DSP33(2), 3xC10s,Ensemble, Twinstore, 218
Music: All Quad incl ESL63.
Kitchen: AD88 (bluetoothed via its I80 dock).
Spare: 101, M2(2) 104 Tuner