I have the exact same issue, here's my perspective:
When loading into the game it displays the mojang logo as normal but continues to never load on the grey screen after that. This has only occurred for the current beta and the previous one before it. There is no way that I have found to fix it and uninstalling the game and reinstalling it will load straight away, but when closing off the game and loading it up again the bug occurs once again. I know that it is not only my device that does this as I have found people also having this issue like yours. For reference I use a Xiaomi 10t Pro.
I play on a Xiaomi 10t pro and it doesn't happen to me.
Yes, I have this exact same issue! This needs to be fixed ASAP because it is a very important aspect to the game that has been working well until the most recent beta/preview.