Well, there is no problem if we log in using VPN and use the same PC/Browser, because the server certainly keeps a log of activities such as cookies and sessions so the server will recognize our activities even though using a different IP. Usually the account will be locked if we log in using a different IP and PC/Browser, but I don't know whether Bitsler implements security like this.
I've been using Bitsler for quite sometime now and I never encounter such problem like my account was locked for using a different IP, PC/Browser. When I visited my friend in Singapore, I logged in Bitsler and I never have such problem, same when I was sent to Thailand for a training no problem whatsoever. You will be asked to verify if its you through an email, but locking the account, no.