I have new M470 with almost default config, now I see that every videos on watchguard support page are not playing, and my onenote application do not sync. How could I find what is blocking my web activity or applications in situation like this?
Look at Traffic Monitor.
It is in the Web UI or in WSM Firebox System Manager.
Look for deny log messages or allow log messages with a proxy strip section.
Post sample log messages, and we can help more.
Also, you can open a support incident and get direct help from a WG rep.
You can do this via the Support Center link at the top