I have a weird issue that whatever I do, the octoprint fails to connect to the internet. If I do a connectivity check to 126.96.36.199 port 53, the test fails. The hostname resolution check works just fine. If I replace 188.8.131.52 by a hostname/port 80, the connectivity check is ok, so there is access to the internet. However I still can not install plug-ins or connect to obico, from obico I get a message it fails to connect to the server.
I'm running octoprint on a raspberry pi 4 which is connected via Wifi to a ZTE H369A router and the dutch KPN network. I have set time and area correctly on the pi. If I SSH to the pi and do a ping, the ping tot 184.108.40.206 fails, a ping to my own website reinierdevlaam.nl is ok.
I'm running out of ideas, please help.