I changed from Sky to BT tv in December and have had 3 Pro boxes and 5 engineer visits since then. All 3 boxes have had the same problems:
1. Failing to turn on first thing in the morning
2. Freezing while changing channels
Both problems fixed by disconnecting and restoring power supply.
The last engineer visit (12 Feb) appears to have solved (so far!) these problems by setting the standby mode to "Always ready" and not the recommended "Smart". This must surely suggest that there is a problem with the Pro box if it cannot function properly on the recommended settings!!
I think the box works perfectly so far (the known issue with wi-fi not working for many has been fixed with the last update).
As for the Always Ready I've been changing that setting for over a decade on anything I can and it was the first thing I did with the Pro box.
A bit of common sense I think. These things need to be 'on'.
This will be of no comfort whatsoever but I've been running one as my primary Freeview source/recorder for a month in Smart standby mode. Only once has it locked up, fixed by holding the front power button for a few seconds as you would a PC/laptop to force a shutdown.
Not that it should cause your issues., but there's an additional deep sleep schedule in the settings menu, so it may be worth checking that's not set to when you use the box early mornings. I can't remember what the default setting was.
When the box has been changed, has the PSU also been changed? That's often overlooked & a new piece of hardware plugged into the same (potentially problematic) PSU.