I just joined the forum to read this in its entirely.
I'm not a Ram Owner, but I own several other FCA vehicles with SXMG and I've had issues with all of them in one way or another. I feel everyone's pain.
Anyway, my 2020 Jeep Cherokee was having these same issues, after an hour, no remote commands from the app or mopar.com.
I reached out to SXMG customer care for other issues and they were, as always 1000% useless.
I escalated the issues to jeep cares. They got me a case started with Uconnect care.
After less than a week, my customer care advocate at Uconnect found a TSB 08-035-20 for my vehicle that was a RF hub update. The RF hub software update said stability of power cycles on RF HUB. Since having the update, my Jeep now accepts commands overnight, 2 days later, etc.
If you are still having this issue, there should be a software update for the RF HUB that takes its software to .AC revision from .AB
If has to be done at the dealer and it takes about 10 minutes.