@BobbiF You got the problem. Should have googled a bit more... My ISP changed to CG-NAT, and then DynDNS is of course lost. Will ask the ISP to get a public IP again. So tp-link was not to blame. But...

Have an issue with DynDNS with my router. Worked fine for months, but the other day my ISP must have done something, and I start getting quite different IP's form them. Used to be 31.x.x.x but now I...