Youtube not playing in Wifi I have this real strange problem that youtube is not playing on my Onda Tablet (dark screen and "problem while playing"), when I am in my home wifi. When I use my mobile as a hotspot and connect my tablet to it (also via wifi) it's working. 
I use several android devices and the Onda Tablet is the only one, which does not play Youtube.
Other Video Players work without problems. This also happens, when I browse to m.youtube.com in a browser on the tablet.
Here's what I already tried:


Clean Cache and data of youtube app
reinstall youtube app
manually downgrade youtube app
changed DNS of the tablet to 8.8.8.8
Factory reset the tablet
Reset my router
My only guess is a misconfiguration in the wifi options of the tablet but I could not find one.


My Tablet:
Onda air v989 running Android 4.4.4
Any help would be much appreciated.
Thank you!
So, I came across the solution for my very specific problem:

My tablet seems to have a problem concerning youtube and IPv6. It's probably some flaw in the firmware. 
After speaking to my internet provider I am now constantly leasing an IPv4 Adress and youtube is working just fine.

If you have similiar problems you should definitly try this out!