Black Chambers massive latency spikes

Act 3 Normal

In Black Chambers portal back to gateway.
Go through gateway and sell, back through gateway to past for portal.
Take portal back to black chambers.
Ping starts fluctuating wildly up to 500+.

It appears to be related to the portal.

I'm able to recreate this every time I try it.

If you portal to gateway but take waypoint back to Black Chambers there is no problem.

Leave Black Chambers through waypoint and return through waypoint, no problems.

Portal out of Black Chambers and go right back through portal, bug starts.

Logging out outside Black Chambers but taking the portal back will cause the bug.

Logging out while inside Black Chambers, the problem may or may not happen, not consistent.

After the bug has started it will not stop until you restart the game no matter how you leave or return.

Happens no matter what server I connect to.

Seems related to returning through the portal specifically.