Hello! I completely understand the frustration with this issue. The team is aware and currently looking into this.
Could you confirm if this is still happening after installing the recent Hotfix 18 and if you are in Honour Mode or not?
All good in the hood, not trying to come across like an angry past the moment person, I understand these things happen.
Can confirm on Hotfix 18 there was still a delay after merchants got axed and still some laggy trading menus with alive ones, but I left the game alone for about 3 and a half minutes after Tali died and it finally finished loading everything back to normal and let me continue, as user psychedelaholic said above.
Also yeah I'm on Honour Mode, haven't played on Hotfix 19 yet.