So, another user reported some connectivity issues earlier. I got one similar to what you got, but nothing strange since then. How did the notification for this reply look?
I know what it is! It is for a version of the app that I haven't released yet. Basically, it is a way for the smartphone to remove notifications when they are no longer needed due to another action.
Sent another update to the play store, should be available soon. I could confirm it working on my end, but time will tell as to if it'll work on the published version.