A licence is a permission in one place, and only one place

The Great Britain register describes what may be offered to somebody in Great Britain. It says nothing about whether the same operator may accept a bet from anywhere else, and an operator licensed in one jurisdiction is routinely prohibited in another.

Gambling is licensed nationally, and in some countries sub-nationally, because it is regulated as a social policy question rather than as a trade. There is no international licence and no mutual recognition, so 'licensed and regulated' on a website is an incomplete sentence until it says by whom and for where.

Which regulator applies to you depends on where you are resident and physically located, not on where the company is or where its servers are.

Which is where it goes wrong. The phrase 'licensed and regulated' is repeated on marketing pages without a jurisdiction attached, and it is meaningless in that form.

What to do with it. Find your own regulator first, then check whether the operator appears on its register. The order matters: an operator's own licence page will always name the regulator that suits it.