[Inf-IT DAVcl] InfCloud is failing on me...

All of a sudden InfCloud is missing events.

I'm running InfCloud 0.13.2.rc2 since the end of 2015 using FireFox on Fedora. The DAViCal server is running on a separate system.

InfCloud didn't change and neither did the DAViCal server. I did upgrade FireFox as part of regular system upgrades.

This morning I noticed, the hard way, that a repeating event was missing from InfCloud. It is just gone. All occurrences, including past occurrences.

The event is on the server, since other clients (Android phones and tablets) display it.

This worries me very much. Is there anything I can do to find out what is going on? I tried cahce_update but that didn't make a difference.

Update: InfCloud with Chromium doesn't show the missing events either.