@SoupRKnowva @LCMusicLover I don't have this issue when using Toslink with M-Scaler.
This is because in Roon, I program Roon to add 2000ms of Resync Delay when feeding M-Scaler via Toslink.
I presume whichever music player you use should have this functionality.
I think the issue comes from M-Scaler "caching"? digital samples for the 1 million taps so it takes a bit of time for it to clear. So if you suddenly change from one sample rate to another via Toslink, unlike USB, there is no way for the DAC to know of the change immediately. So it takes a while for the M-Scaler to adjust and the two sample rate signals get mixed together?