Interesting. I've tried 1E0, 19E, and 1FC which you monitor.
1E0 has 55 pending decodes, none decoded yet
19E has 2 pending over 1000 decoded
1FC has 28 pending over 1500 decoded
So, all are working, look through your radio files and see if at the end there is a long string followed by the alias in quotes. Perhaps they decoded and the unit hasn't transmitted again. You do have internet connection correct?