Sanctum Assassination Bounty resets progress on Host Migration

[DahliaYmir]

I was doing a Sanctum Assassination Bounty with one other random person. At about halfway through (25ish of 45 murmur eyes), they left, triggering a host migration.  When the game returned - the bounty progress reset to 0/45, while the mission progress remained at 25/45.  Thus, I was only able to further progress the bounty to 20/45 before the eye stage finishes and no more spawn.  Even after finishing the Assassination target, I could not extract due to the bounty not being completed, which at this stage, was rendered impossible to complete.  My only recourse was to Abort the mission, costing me all of the loot I had obtained.