I don't know if this is a wider issue or only me experiencing it, but has been occurring for the past 2-3 days.

On some characters, different instances have drasticly different connection feelings. For example:
On my magden, Elden Hollow 1 felt completely normal, the next dungeon I queued into was UNPLAYABLE lag, comparable to a 'whole of cyro zerg vs zerg fight in primetime'. Grahtwood unplayable, cyro normal. And it differs on different characters.
A bit more info for context:
-This is at about 10pm AEST so not primetime by any means, quite the opposite.
-Xbox Series X, 30mbps download, 5mbps upload, 166ms ping, 0%packet loss. Confident this isnt a network issue.

What I have done to try narrow this down:
- Reset the console, reset the modem
- Deleted saved data from the console
- removed alternate MAC address
- Tested on multiple characters
- Tested if keeping character item inventory below 100 helped (rumour I heard) it didnt.

Please help this is very frustrating, the only other thing I can think of is reinstalling the game.