Problems connecting over WiFi

[Goodstuff]

While on cellular network the "connecting"-phase lasts for a second or two, but when I'm connected to wifi at home it's usually appr. 20-30 seconds. And I have tried every possible settings on my router but nothing seems to help.
I have experienced this issue for a long time, not only on this device. But I think its becoming worse and worse.

My specs:
iPhone 7 (128gb) ios10.1.1 Spotify 6.8.0.3786
I have a 100mbps fiber connection and modern router. All other online services work like a charm. But something is off with Spotify and this endless Connecting.

[feelikeastrangr]

Hi @Goodstuff, so you're able to get on, its just that it takes 20-30 seconds for Spotify to load up via wifi?

Check this support page to start with troubleshooting mobile connectivity issues: https://support.spotify.com/us/using_spotify/troubleshooting2/mobile-connection-troubleshooting/

Suggest a restart of your router and a reinstall of the app. Let us know how you get on!

[Goodstuff]

Did a factory reset of the router, and reinstalled the app. No improvement at all unfortunately.

[Goodstuff]

An update:

I have made several additioinal experiments to close in on the core issue here.

The problem seems to be located in my router's firewall.

During the seemingly endless "connecting"-period the logs in my router reports multiple messages like this:

[INFO]	Tue Dec 27 14:41:37 2016 Blocked incoming TCP packet
from 194.132.162.36:80 to XX.XXX.XXX.103:51521 as
PSH:ACK received but there is no active connection

After googling a bit further this is supposedly fixed by setting a less restrictive policy in the router's firewall, "set Firewall settings to Endpoint Independent for TCP and UDP under Advanced/Firewall."

Unfortunately this did not help either.. I tried turning off every possible firewall setting I could find in the router. leaving me completely exposed.. but still the blocking of these TCP connections persisted. What is the Spotify-app doing during the connecting-phase that is different from most other apps?? I have no issues with any other service like this.