Again, Brexit!

EU representative if subject to the GDPR on the basis of Article 3(2)
Like many other non-EU-based controllers and processors, UK entities subject to the GDPR as a result of their remote commercial operations or online profiling activities in the EU will need to appoint a local representative. Again, this is not a simple exercise, as it requires some strategic thinking as well as specific practical steps to make that appointment valid.”

A good analysis by Eduardo Ustaran is available here