how do you figure out what and where you may need to whitelist?

[consorts]

over the weekend a friend lent me directv creds which allows roaming clients to view on demand (not live).
at&t streams work best on google chrome, needs flash, but it depends on a stream drm manager running;
https://www.file.net/process/ciscovideoguardmonitor.exe.html
it kept getting stuck reinstalling this drm (even installed correctly) because something was blocking it.
i know this because when i used it with a paid vpn active to a local virtual outlet, it worked perfectly.
so i'm forced to conclude something running in my router blocking it - which i'm fine with, except
i have no idea how to isolate what's doing it and exactly what ip or url i would need to white list.

this anecdote begs the wider question for popular merlin apps users here;
how the hell do you guys figure out where and what to whitelist when you have so many layers of protection?
i for example have; aiprotection, cloudflare, diversion, skynet (nvm the client based am/av/fw i can disable)
and any one or more of them could be contributing to blocking parts of this at&t/cisco drm confirmation app.
i know i could just get a free copy of wireshark and run that, but to the uninitiated - that program is a mess
giving you far more incoherent information to sift through than mere mortals can possibly comprehend

so i ask you all, short of continuing to use a vpn to circumvent my own router, what's an amateur to do?
to clarify, i have no need to fix this specific issue, rather gain methods to approach the broader concern.

another common example is my family runs into many retail referral sights that won't work on my router
and again, even if i whitelist the url is seems to get hung on in diversion, it's still getting hung up elsewhere,
yet the moment i activate my vpn to a regional outlet - everything works perfectly, meaning it's the router...

 

[ColinTaylor]

In general terms the typical troubleshooting method would be to disable all of those things to start with to confirm that it is actually a local problem and not something external (like your IP address has been blacklisted). Having confirmed that it is a local problem then start re-enabling those things one at a time until you find the problem.

Any finer-grained analysis beyond that point would depend on the particular piece of software concerned.

 

[GHammer]

Well, it's not 'the router', it's the additional capabilities you have added/enabled.
It sounds like you have added a lot of ad and tracker blocking that comes back to bite you.
I'd look at the lists these things use and maybe try enabling only the malware lists.
You'll certainly see ads and probably be tracked but the referral links and things that you seem to need will work.