Rebuilt PC - Splashtop Personal "Cannot connect to your computer."

I had Splashtop Streamer on three computers on our network, and recently rebuilt one of those computers (new drives, so a fresh WIndows 10 install.) I re-installed Splashtop Streamer and logged in, but I cannot connect to it. Splashtop can see the computer, but after attempting to connect, I get the error message "Splashtop Personal Cannot connect to your computer."

I think all of my settings are the same as the previous build, but I just can't get it to connect.

I'm uninstalled and reinstalled Splashtop Streamer multiple times, including using RevoUninstaller to clean up extraneous bits. I've told Comodo Firewall to allow it, added port 6783 to the firewall, and even tried running it with the firewall disabled, but still cannot connect.

I'm running Windows 10 Home, build 19042. Comodo Firewall. Windows Defender AV (and everything else but the firewall.)

Splashtop streamer 3.4.2.2

I've run out of ideas on how to make the work.

Thanks,

Julian