Comcast new router: couldnt log in steam client

[Asaki]

I changed a new router last Friday (the previous internet is from Comcast, it doesnt changed ), which Comcast says it will make internet faster (yes it is faster). But since that, I could not log in steam client. I tried other wifi in Starbucks, I logged in. I had talked to four analysts: the first two changed (i think) my router setting or something like that, and its not working. The third person asked me to unplug the router and plug in later, I did and I could log in steam client for ONE MINUTE. Then I lost connection to steam. The last analyst said he couldnt help me after he asked for a lot information. He said he did every try and it has to be steam problem.
WTF is going on?! Is Comcast blocking steam or I just cant connect to steam server by XFinity? Do I need to change a server?
Suggestions Plz, help me!!!! Thx so much

[Tev]

Try another computer in the same network; if the issue persists - then it's likely your router's port problem.

https://support.steampowered.com/kb_article.php?ref=8571-GLVN-8711

[Asaki]

Originally posted by Teutep:

Try another computer in the same network; if the issue persists - then it's likely your router's port problem.

https://support.steampowered.com/kb_article.php?ref=8571-GLVN-8711

Thank you for reply, I will try it tomorrow.