I am facing the same issue as well. Cannot see any club activities being published since afternoon (last 6 hours).

Looks like its updating now, might be a temporary outage

There’s no incident mentioned on the Strava status page but there was a significant peak in activity uploads several hours ago, so it was probably it:

Hi everyone, appreciate the flag here! Let us know if the issue is still persisting. In the meantime, would also recommend bookmarking Strava's status page (great shout ​@Jana_S!)  in case you experience any issues down the road - it’s a great first resource to check out!