I’m glad you were able to resolve your issue.
I noticed in an earlier post that you also had “Enable Port Trigger” = “Yes” on the Asus router. It didn’t look like you had any port trigger rules defined, so you may want to consider disabling this if you haven’t already.
(If you are interested in seeing the manual port forwarding setup I have on my Asus router, please let me know. I already have it typed up, but it’s very similar to what you already tried. I also don’t have a cable modem that was causing troubles, so the environment is a bit different.)