A UKGC licence is the starting point, not a guarantee of a smooth experience....

https://josuesexpertblog.novacrestiq.com/posts/bank-transfer-vs-card-vs-e-wallet-withdrawals-which-is-quickest

A UKGC licence is the starting point, not a guarantee of a smooth experience. Check whether a site clearly lists slot RTPs, explains how long withdrawals usually take, and offers practical responsible gambling tools such as deposit limits and time-outs