Hanging workunits?

For your situation, possibly yes.

You seem to have lots of active projects sharing your host. Because of how many there are, BOINC will probably be stopping some tasks and starting others on a fairly regular basis in order to share your resources 'properly'. This is fine (in theory) but may cause some issues if tasks are not "kept in memory when suspended". How do you have that preference setting set? You seem to have 8GB RAM. How much of that do you allow BOINC to use?

If a task gets suspended when BOINC chooses to change projects, there'll be no problem if it can be kept in memory. If the setting is not set, or if there's not enough available memory to allow suspended tasks to remain memory resident, you may lose some crunching time if a task has to be restarted from a checkpoint saved on disk.

With the S6CasA run, checkpointing is rather infrequent, so perhaps you are seeing tasks being restarted at an earlier stage due to this behaviour. If you are referring to FGRP3 type tasks, it may be a somewhat different issue.

If you gave more information about your setup - preference settings, type of jobs you are running, how many partly completed tasks there are 'waiting to run' (for all projects, not just EAH), etc, it would be easier to give you a better answer.