The minimum free disk space (2000MB) reached for /app/list/splunk/var/run/splunk/dispatch.
However, I have checked and there is no data on this directory. Do you know, when you are searching data on the indexers, if the result of the search is stored on the master dispatch directory or the indexers dispatch directories?
The files of a search will be deleted when the lifetime of it expires (after a few minutes).
Your folder has a minimum free space configuration which has expired for this particular folder. The same propably applies to the whole splunk directory. You can reduce the minimum free space for the splunk folder in server.conf
Searches results are stored in $SPLUNK_HOME/var/run/splunk/dispatch.
Searches have a lifetime and probably when you see in the directory they were expired.
Otherwise, did you checked the maximum space availability for your role? I had a similar problem and the solution was to enlarge the space for searches for the role admin.
you can do it in settings - roles.