The 10.9 version of Jellyfin or rather the web client seems to have serious issues with caching.
You could try to log off from the clients that don't work, clear the cache if it's a browser, kill the app if it's an application, then log back on again and see if this does the trick. I had similar issues after upgrading from 10.8.13 to 10.9.6.
My friend's Jellyfin app on his Android phone is stuck on the Jellyfin logo since the upgrade. We haven't had a look at this yet as he normally uses a browser on another device but it could be a related issue.
You could try to log off from the clients that don't work, clear the cache if it's a browser, kill the app if it's an application, then log back on again and see if this does the trick. I had similar issues after upgrading from 10.8.13 to 10.9.6.
My friend's Jellyfin app on his Android phone is stuck on the Jellyfin logo since the upgrade. We haven't had a look at this yet as he normally uses a browser on another device but it could be a related issue.