So, i have a R-notebook with different cells and a '15.4 LTS ML (includes Apache Spark 3.5.0, Scala 2.12)' cluster.

If i select 'run all' all cells will be run immediately and the run finishes quickly and fine. But if i would like to run the cells one by one, the cells often wait for a very long time (half an houre or an houre) to run or it just will not run.

I checked some logs on the cluster but i could not find anything why it's waiting. i am the only user of the cluster.

If i restart the cluster i can run all the cells at once again and it goes fine.

How can i solve this and how can i check what is happening on the cluster and why it is waiting to run my cell?