Eventually I unchecked the option, and rechecked it, and Tablo said all was good. A quick test via my cell phone w/ WIFI off confirmed everything was fine.
As Rich stated, don’t rely on the re-test page with the red arrows. I probably set up and deleted the port forwards 5 or 6 times and I knew they were correct, but the re-test page would never update with green arrows like the instructions said. I eventually disabled and re-enabled Tablo Connect in the menu and it worked just fine.