[EasySt]

One issue you can run into is that with a VPN, you may wind up assigned an IP
address that was already used by someone else to do something ban-able, or
worse, and THAT will be the cause of your failed registration attempts and such.
(Using a VPN supplied ip address previously banned for someone else’s activity.)

When that is the cause, reconnecting to get a different IP can often let you proceed.

[Bikkuri]

"When that is the cause, reconnecting to get a different IP can often let you proceed."

Correct. And I usually reset the assigned IP twice a day (to make sure I have the fastest connection).