Feels like a silly question, but someone please shine a brilliant light on this: Since a few days, none of the rep changes occurred "in green" on any of my devices, (so not) like this:

just the number changes. Also missing many of the pings. It happened to me occasionally in the past, which made me shrug, since it was only occasionally. Seems all the time now.

Devices:

• Desktop box Ubuntu 18.10 / Firefox 67.0
• Laptop Ubuntu 19.04 / Firefox 67.0
• Android 6.0 Phone / Chrome 74.0.3729.157

What could be the cause?