The screen showing the number hint was removed from the game in a 2019 game update.
Prior to that, many players reported not always seeing a number on the screen above the injured alien in Maray.
Though many reports were recieved, reproducing the issue in-house was not possible. Therefore, developers could not create a fix for the issue.
Subtle hints in the Mayor's behavior throughout the game already existed, allowing attentive players to consider checking the Mayor's cryopod, listed in the journal on the table in the same room the alien is in.
Checking that pod (#222) is what enables that final door to open in Maray.
Removing the screen hint to allow players to focus on the more subtle path was decided as the best resolution to the problem (and is the solution that would not break the game even further).
NOTE: Some walkthroughs still show that players should see the screen light up and show the number, but this will not happen in any Obduction builds for any format (PC, Mac, PS4, Xbox) post-2019.