The version of emonCMS running on that Pi was low-write 9.8.31 | 2018.06.21. I am not sure how to find which version of emonHub. But in any case, older.
I tried using minicom to connect to the RFM69Pi running on my emonCMS server and was able to confirm that it responds to ‘t’ and ‘v’, which is consistent with the idea that communication from the Pi to the RFM69Pi is not the issue. (Testing with another Pi and another RFM69Pi is a habit because minicom hijacks all the data going to emonCMS while I am testing. But in this case the test setup isn’t sending data from the Pi to the RFM69Pi. I am going to assume that is some problem with the serial setup on these test Pis I had sitting around and not worry about it for now.)
In other news, I just found this post that would suggest I might have to update the version of jeelib I use on my receiving node. I have been using the OEM specific fork, but it appears @alandpearson used the latest jeelib on the emonGLCD receiving side? At least, that it how I read the thread so far.
https://community.openenergymonitor.org/t/emonglcd-sketch-issues/9715/41