In Epic Backlog with Portfolio selected in tier1, when not all of the Epics are loaded, using 'Move to Bottom' assigns rank 10000 and leads to inconsistent results

Issue Summary

In Epic Backlog with Portfolio selected in tier1, when not all of the Epics are loaded, using 'Move to Bottom' assigns rank 10000 and leads to inconsistent results.

Results observed so far: the Epic disappears from the list until the page is refreshed, or gets assigned to a rank that's not bottom, or goes to Parking Lot.

Steps to Reproduce

1. Select a Portfolio in tier 1 filter with with enough Epics that they don't load in one go (~200-300 Epics)
2. Go to Epic Backlog
3. Expand the backlog, but do not scroll down to prevent the rest of epics from loading
4. Right-click on any Epic in backlog and click 'Move to bottom'
5. Scroll down to load the remaining Epics and look for the moved Epic and its rank
6. Open the Epic's Audit Log and notice it was moved to rank 10000, even though there aren't 10000 items in this backlog

Expected Results

Move To Bottom: Move the work item to the bottom of the list the work item is contained in.

The Epic should be still in the backlog but now in the last position.

Actual Results

Between different test environments, we've seen multiple inconsistent behaviors like:

• the Epic disappears from the list until the page is refreshed
  • It can appear in the same position after refresh, or new position
• the Epic gets assigned to a rank that's not last
  • in the below screenshot it got assigned to position 296 out of 342 and was visible when loading new items
    
• the Epic goes to Parking Lot

Workaround

Scroll down to load all items including the Parking Lot before ranking them.