I signed up for Twitter last week, and within minutes my status changed to "Your account is locked", because my account broke the Twitter Rules. I am still trying to figure it out.
They lock your account until you give them a valid phone number, it's probably nothing you did just they use 'dark patterns' to get your data. Everyone's probably better using Mastodon or something.
They are likely using some fuzzy logic to detect people evading bans by creating multiple accounts. Could be some combination of IP address, OS, browser fingerprinting, etc.
This approach inevitably results in some amount of false positives, but nobody cares since the users aren't the paying customers.
Facebook does the same thing. I had a secondary IG account created in 2013, which worked fine until late 2021, when it refused me access without submitting a phone #. It was a burner account so it didn't matter, but still, very irritating.