I could hot-fix this problem by changing network configuration via nm-connection-editor. In my case the "Connection priority for auto-activation" was set to -999 for one Ethernet configuration. After changing it to 0 and reconnect, the icons re-appeared. So it is maybe an issue of malformed/weird configuration.
I could hot-fix this problem by changing network configuration via nm-connection- editor. In my case the "Connection priority for auto-activation" was set to -999 for one Ethernet configuration. After changing it to 0 and reconnect, the icons re-appeared. So it is maybe an issue of malformed/weird configuration.