Map Device Portal Disappear after Stutter-Freeze

I just witness an annoying bug:
1) I'm running Vaal Factory T15 map
2) I'm almost done with killing all the rare mobs to mark it completed
3) There's still all the additional stuffs I am saving for the last
4) I got 2 white strongboxes I need to spice up with Alchemy and Exalted orbs
5) There's 1 breach hand not opened yet
6) Delirium mirror done
7) Someone pinged me for trade
8) I TP-ed back to my Hideout and completed the trade
9) Was sorting out things at my stash
10) Game froze, I thought it's going to crash, like any other random time
11) 2s later, game resume movement and my portal DISAPPEAR!!!
12) So many items not picked up yet from all the dead monsters' bodies

May I point out that, if I didn't die while mapping, the portal shouldn't disappear. Even when all rares are done, I still got other things to do inside and it SHOULD NOT CLOSE for whatever reason! ESPECIALLY crashing or bugging or glitching out!

There are times I got DC from the game. And when I managed to login back, usually within 1 min, the portals around the Map Device disappear. Atlas map mark it as "Map Attempted" and I have to put in another waystone to run it again to mark it green and completed.