ALAC Apple Music files on iPad Pro (gen 3) not playing on DAC with USB C to USB A cable

I am unable to playback Apple Music from my iPad Pro M1 (Gen 3 iOS 18.3.2) connected via an Apple brand USB C to USB A adaptor cable to the (5V 2.1A) USB input on the front of my Rotel RA1592MKII integrated amp. The DAC on that amp is capable of decoding PCMNsignals up to 24 bit, 192kHz. Looking for a solution.

Note that I can’t play back any Apple music in any file format, be it AAC or ALAC files, with and/or without Lossless enabled or on each of its sub-settings (i.e., high, lossless, high-res lossless). I have also tried several other audio/data/power capable high-speed USB C to USB cables by Anker and other manufacturers that should work, but none of them do. I DO get power on my iPad when alternate inputs are selected on the amp, but that diverts to battery power when the proper USB input is selected. And regardless, I get no sound on the audio system, only on the iPad (which doesn’t indicate it’s connected to the amp.)

Here’s the thing: I CAN play my Lossless music via my IPhone Pro 14 using a lightening to usb connector. I have ALSO tried connecting that same Apple lightening to usb cable to my iPad via an additional Apple lightening to USB C adaptor. Same result, no sound.

Is there a specific adaptor cord that I need to play music directly from iPad Pro (Gen 3) to the Rotel receiver using the USB input? What is it about the USB C connection that is causing the problem not experienced on the lightening connection? And are other there other solutions that would work, such as a USB to Digital input cable (coax or optical) that uses the amp’s built-in DAC? And do portable external DACs typically have this problem with recognizing iPad Pros with USB C ports?