2026 Update! For anyone else curious about queued jobs, be sure to see → How to see the UseGalaxy.eu job queue statistics - #2 by jennaj
The clusters were probably just busy. Some of your jobs run, some of other people’s jobs run, more of yours, repeat.
Larger jobs will require larger cluster resources, and those tend to the “busiest”. Why? These are already running larger jobs, so take longer to clear out for new jobs. Smaller jobs run on smaller cluster resources, and those turn over jobs quicker. This seems to match your observations.
I don’t know of anything special going on at the EU server except for the holiday. And … holidays tend to be a popular time for people to do data analysis! Any related bottlenecks should clear up soon. The best advice is to use workflows to get everything queued up, and to use the notification functions.