That makes sense, actually: the line out would be bypassing any processing. If you're just listening to a stereo source, have you tried adjusting the mode to potentially bypass or minimize the processing delay on the sound coming from the AVR?
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Would probably try "Native", or if you have a subwoofer that you want the crossover to still apply try "Stereo 2.1".
When you say you want to do this to listen to Tidal, I assume that means you are using Tidal Connect directly to the AVR?