Similar issue here, except not during showdown.
Perfect Run objective is broken on hardcore mode and causes a mission failure even though itself and all the requirements are completed.
PC of course, though I don’t think this is a platform specific bug.
And before anyone asks, yes this bug occurs with or without mods and no, it’s not caused by mods.
Platform: PS5 (Digital)
Location: Paris (Freelancer)
During a Showdown, I had a reverse Perfect Run bug, where I got credit for a Perfect Run despite not completing one of my objectives. I also seem to have gotten the 1,000 
for the objective I failed. 
I had the same “problem”. Lindolfo had a possible explanation for it, that also holds water in your case:
This might not be a bug but a feature withholding an existing reward for collecting everything until IO is finished including all intended content.
100% agree. If it weren’t intended to be absent, there is no way it wouldn’t have been fixed back in May tbh since its a relatively simple fix.
Platform : PS4
Bugs in Elusive Target AGAIN and AGAIN.
The challenges of the Appraiser did not pop out and I know that… IOI make it happen again and again…” so can you fix my carrier record? Thanks.
Platform
PS5 Digital
Location
Berlin
Contents
During the leader showdown at the end of stage 4, the target’s leader went down into the wall and was completely out of control.
I don’t like disconnects, but this time I had no choice but to redo this target,
but, the target did not move at all voluntarily until I used “Seeker 1”.
Steps to reproduce
1. do the final mission in Freelancer mode in Berlin.
2. the target is randomly determined.
3. the leader is inside the wall and cannot be reached.
Frequency of occurrence
Only once.(However, the same was true after the line was disconnected.)
https://www.youtube.com/watch?v=sn6BipAMSH0&t=14615s
4:03:35～
Platform: PC/Steam
Location: Isle of Sgàil
Description: Already completed The Appraiser - Year 3 Elusive Target with a Silent Assassin, but the corresponding challenges The Appraiser - Year 3 and Silent Assassin - Year 3 didn’t unlock.
Noted that the previous Elusive Target in Isle of Sgàil, The Stowaway, still shows The Stowaway - Year 3 and Silent Assassin - Year 3 correctly.
I actually thought this bug was fixed - I knew it existed, but having completed quite a few missions with similar objectives + perfect run I though it was working correctly - but apparently it was not.
The image below it is after hardcore showdown on Maldives, at least it was in the early stage.
Is this bs planned to be fixed in the august patch ?
It even listed prestige objective as completed on the detailed score.
The Prestige objective that only unlock as you exit are consistently successful failures in Hardcore. Only use prestige objectives that can actually be unlocked during a mission.
Platform: PC (Steam)
Location: Marrakesh (bug was discovered at this location)
Description: No fire accident kills animation (NPC or target just stands and screams)
I first discovered this bug in Marrakesh when I shoot the oil puddle in the tunnel where both targets meet. Later, the same bug was discovered in The Appraiser ET on the Isle of Sgàil.
Steps to reproduce:
Frequency: Always happens for me
Platform: PC, Steam
Location: Dubai
Description: Some people disappearing, only visible from one side.
Frequency: First time happening to me.
Platform
PS5 Digital
Location
Isle of Sgàil
Contents
Target “LARS VEGAS” does not move an inch.
Steps to reproduce
Frequency of occurrence
As far as I can remember, this is the third time.
https://www.youtube.com/live/fMrj11RYhBk?feature=share&t=6823
1:53:43～
Translated at DeepL.
Platform: PC / Epic / digital
Location: Sgail
Description: Once again, Elusive Target challenges have failed to unlock, this time for The Appraiser (Year 3).
I have completed this ET, but neither of the two challenges that should have unlocked have done so.
Steps to reproduce: N/A
Frequency: Has happened before with other ETs.
Screenshots:
Platform: Xbox One.
Location: Safe House.
Description: cannot pick up scalpel from infirmary.
Frequency: happened once.
Platform
PS5 Digital
Location
Marrakech
Contents
The target “Toby Jones”, who smokes shisha with emetic poison, does not become emetic poisoned.
Steps to reproduce
Frequency of occurrence
Occurs once.
https://www.youtube.com/live/z_FapJpCuDA?feature=share&t=10660
2:57:40～
Translated at DeepL.
Platform
PS5 Digital
Location
Hokkaido
Contents
The supplier in Hokkaido are unable to trade for forever.
Reproduction procedure
Frequency of Occurrence.
Encountered about 3 times.
https://www.youtube.com/live/pi_zMBUscZo?feature=share&t=4303
1:11:43~
https://www.youtube.com/live/pi_zMBUscZo?feature=share&t=4450
1:14:14~
Appears to become untradeable.
https://www.youtube.com/live/pi_zMBUscZo?feature=share&t=12413
3:26:53~
Other NPCs do not have this problem.
Translated at DeepL.
Platform
PS5 Digital
Location
Ambrose Island
Contents
”SAWED-OFF BARTOLI 12G" on Ambrose Island cannot be taken home.
Reproduction procedure
Occurrence frequency
Always.
https://www.youtube.com/live/pi_zMBUscZo?feature=share&t=12840
3:34:00~
Translated at DeepL.
Platform: PC
Location: Mumbai
Description: The target disappears from the surface.
I walked quietly towards the targets then she disappeared without any action on my part.
Frequency: This happened twice in the same place and another person had the same problem.
https://www.hitmanforum.com/t/freelancer-general-discussion/17691/1123
