Suspect they've made their choice in the fifteen months since asking.
Can't work out why you didn't return it. Seems semi functional at best.
Though suspect many of the issues you have would be same in the Denon as they have far more in common than different.
Well that may be less of issue next year
"Apple Music plans to launch a dedicated classical music app next year combining Primephonic’s classical user interface that fans have grown to love with more added features."
Only things I can find on a search are people moaning that they didn't do a black friday deal last year and further back that 2019 they seemed to choose that time to raise the price from 499 to 699.
Sales don't seem to be their thing.
Are you running it from micro SD, was reading that Android doesn't run well from that. Might be worth trying from USB drive if you have one lying around.
Pity that USB sound didn't work as that's listed as being working. Oh well