App does not log in to the blynk server while on Wifi

Hi there,
If I try to log in the Blynk APP while I´m using my WIFI at home it does not log in and there is a red note “reconnecting to the server”
When I switch of the WIFI in my smart phone than the App will connect emediately and every thing works fine.

I did not find any post on that issue so I opened one.
Actual I do not use a local server
I´m using and talking about the blynk server which should be connected by the app.

Thank you for helping me.

Hi. Probably your router blocks 8443/8442 ports

Thank you.
Your are right there was a restriction set in my Fritz!box which I did not know.
Now it works.