Netflix app does not login anymore

I have the following puzzling situation. Since a week or so, on my various ios devices I cannot get the Netflix app to work anymore. But only on my WLAN at home. With a different WLAN someplace else the app works fine. (All other streaming apps work btw.) The puzzling bit: Using Safari on MacOS I can login and use netflix.com as usual on my home network.

I am not aware of changing my Time Capsule settings or (BT) router settings. No restrictions are enabled.

Any ideas?