VERY loud sound when switching songs sometimes on Apple Music

I have a Mac Mini M1 hooked up to an external amp through the headphone jack. Normally this works just fine. However, ever since upgrading to Apple Music 1.1.5.74 on Mac OS 11.4, and turning on lossless audio, sometimes I will hear an EXTREMELY loud sound.

A few things to narrow this down:

• Mac Mini is outputting to headphone jack through a 3.5mm to RCA adapter to a Denon AVR-786 receiver.
• My amp is turned to a nominal volume -- comfortable, not loud at all.
• Apple Music volume is at about 25-50%
• I have Lossless audio turned on.
• The Mac will emit the sound at the SAME LOUD VOLUME (I estimate >90 decibels of distortion for about 250ms)
• This only happens occasionally, and only when choosing a new album or channel. In other words, I never hear it during an album (thankfully); it changes songs fine. But if I switch to a new album, there's a decent chance it will happen.
• The sound is a very dissonant distortion sound and is so loud it defies the logic of it being a sound coming through the digital signal -- meaning I interpret this as something that is happening POST-DAC. There's no other explanation. I have my volume set so low that even a high amplitude digital signal would not make that sound. It's almost like the DAC itself or an internal pre-amp is turning off and then ON again and emitting this sound. But again, it is seemingly random other than when I select a new song. I haven't paid attention to whether it happens only on Lossless songs, but most of what I'm playing is Lossless.
• To be clear, I do NOT have an external DAC. This is a pure analog signal going to RCA inputs on my receiver. I'm going to try to go USB->TOSLINK on the Receiver to see if I can avoid it (or isolate it).