Can’t access Arduino Webserver over Wifi

I’ve got a simple Webserver running on my Arduino uno with the Ethernet shield.
Arduino Uno is connected to a router via lan.
My pc which is connected to the same router can access the webpage but my iPhone can’t access the website over WiFi when it’s connected to the router. I think it could be my firewall blocking requests from WiFi to LAN devices but I didn’t find any option to turn it off...
The Arduino has a static ip...
My code seems to be fine too because it works on my pc.
I don’t need to access the Webserver from outside my network.
What could I try?

Does this work with any other phones? And also confirm that your phone is seen in the router's list.