A problem has been detected where Jellyfin was causing problems with the SD-JSON service leading to accounts being temporarily blocked.
The SD-DD service isn't affected
12/18 Update: The block occurs after 5000 login failures in a few minutes.. basically a denial of service attack. If you disable Jellyfin's grabber and switch to XMLTV source, open a lineup support ticket, request a ban remove and include your ip address (you can get it here).
We're working with the Jellyfin devs to isolate and fix the probem.