Why Twitter detects suspicious behaviour

Can anyone advise me on why Twitter detects suspicious behavior and imposes a temporary block when I create Twitter accounts even though I am using a VPN and grabbing a phone number for verification purposes from the getsmscode service? I also do it in an incognito window. For one account I had to quickly create an email address (as I had created it with email verification and entering the phone number was not enough to unlock it). What does Twitter pick up on as being suspicious and what can I do to avoid? By the way, I also connect the VPN to the same country as the country code for the verification mobile phone number. In addition, I was adding some bio and following a few other accounts when creating the accounts.

most vpn's are already abused a lot since the ip has been used by a lot of people before you, So it is a very real possibility the ip is already blacklisted. And using incognitio browser is not enough to stay hidden

If the IP you have used is blacklisted and used before, it can cause trouble.

I get this on Twitter every time I create accounts even I use unique IP from my mobile phone network. I think Twitter locks every new account and requires phone number verification when you make it.

Thank you. I see that there are some VPNs which provide unique dedicated IP addresses. Maybe that will get around it.