No idea if this has been addressed or not already but I will give it a go.
Whenever another player starts another SR run and few stay in the splendors area (still collecting loot and such, selling, overlooking items, etc., etc.) & another run has already been done - loot chests start to break and sometimes appear as only 2 or 3 are available while other already looted, even though a fresh run has already been finalized.
The solution might be not as simple but how about when approaching chunk 4 all people in splendors gets automatically teleported back into action which is chunk 4, which should solve this bug.
And it is true, we could ask each one individually before Chunk 4 appears (who randomly connects and stays there) to move out of that area but that’s just not a thing someone would like to do each time and every time. 