Need help setting up remote access

I have the Comcast router/modem and I have my Linksys WRT1900AC router, which are both set up. I can’t disable Bridge on the Comcast router/modem because it won’t connect my Xfinity security router, which relies on the Comcast router/modem to work. I did disable the wireless on the Comcast router/modem. I’m using my Linksys router for Wifi only.
I added the single port forwarding in my Linksys router and I checked the box “Manually specify public port”, then clicked on Retry, but that didn’t work. I’m sure other steps are missing, but don’t know what else to do.

I’d appreciate a little help in getting this set up correctly. Thanks in advance.

You have to also set up port forwarding in the Comcast router, too. Here’s an example of how to do both routers:

The Plex server IP is 192.168.1.100
The port you want to use in remote access is 45888
The IP of the Linksys router is 192.168.1.1
The IP of the Comcast router is 192.168.0.1 (this will be the WAN IP listed on the Linksys router)

Linksys router-
Make a port forward rule that points to 192.168.1.100, internal port 32400, external port 45888, protocol TCP

Comcast router-
Make a port forward rule that points to 192.168.1.1, internal and external port 45888, protocol TCP

I followed what you suggested and still nothing. Maybe I am doing it wrong?

Comcast Router

Linksys Router

I decided to remove my Linksys router, so now I’m just using the Comcast router. It’s still not working. Help!