Two Identical Lightsail Plesk Instances Very Different Performance

I've set up 2 idenical lightsail pldesk instances, one in Germany and one in the UK. The German one is performing fantastically. I'm getting good response times from my websites and plesk.

The UK one is extremely slow. I've disabled all my web sites on that instance and still plesk is almost unusable (30 seconds to switch pages).

I'm connecting from Germany, but I can't imagine that that is the problem here.

Any ideas?

Thanks

Peter