TCP Port 37?

I have a Roamio OTA and a Tivo Mini which have been successfully connected (via MoCa) to each other and to my home network for more than a year. Everything was working fine until recently.

Now I'm unable to use the TiVo (iOS) app to do anything. When I launch the app it is unable to connect to my TiVo box. However, the TiVo can connect to the TiVo service (through the network) without difficulty If I try to schedule a program or anything else using the app, it fails. (This used to work...

TCP Port 37?

TCP Port 37?