Execution steps sporadically loading very slowly

We routinely have the 'spinner of death' when trying to open or during execution.  We sent a .har file and were told to do regular re-indexing and clearing cache (Setting --> Apps.  Within the left pane under Zephyr Squad click 'General Configuration'.  Within that page scroll down to re-indexing:  Project MetaData (all project or specific project), then Project Execution (all projects or specific project.  We do the specific one that is reporting the spinning/slowness.  Then scroll down to clear cache and permission cache).  This only resolves for a short time.  Have put in multiple tickets, but same suggestion to re-index, which cures for a 1/2 day, day, or a week or two, random.  No root cause at this point, but does get the Testers moving again.  Word of warning: Have all testers log out of Zephyr before starting, the longest it's taken is 26 - 27 min, shortest 9 min for the re-index of project executions.  A couple times I think someone got back in and had missing test cases or folders, had to re-index again, which resolved the issue.