Ah yeah my MSFT is in a state where everything is usable except Mojang account transfers. Support was unhelpful to gracefully resolve the situation, and recommended I give up and create a new MSFT account to hold the Mojang account, which I ended up doing. So now I have several MSFT accounts to hold various Mojang accounts.

That is every company these days. If you don't give them a phone number they assume you're a bot. The only people who know how to avoid this are the people who run bot farms.

This is exactly what happened to me three weeks after I migrated my paid Mojang account to a new Microsoft account in 2019 or so.

Haven’t played Minecraft since. Every so often I check. The account is still locked.

I wonder why they even keep the "suspicious behaviour" front. My account got locked within seconds after creating it and I had to add a phone number. Who are they trying to protect against? Scammers who bought Minecraft? I didn't even have a chance to behave suspiciously.

It's an excuse they don't have to explain, citing "security reasons". It's an entirely suspicious way to run a business.

It is almost like it isn't about suspicious behavior at all!

and when I decided to give my phone number, they couldn't send any SMS confirmation because it seems their sms provider didn't support my country.