MLB The Show 21 update 1.07 was released today by Sony San Diego Studio. This patch implements a number of bug fixes as seen in the patch notes.
After the small hotfix that was deployed recently, another update has been released on May 14 which is another similar hotfix. This patch addresses an issue with the classic stands in created stadiums that used to disappear leading to an awkward glitch that showed the fans floating in the middle of the air. The patch version is 1.07 on PS4, 1.007 on PS5, and 18.104.22.168 on Xbox One and Xbox Series X|S.
You can find out the patch notes for this update below.
MLB The Show 21 Update 1.07 Patch Notes
This is a small update that fixes a bug that would cause classic stands in created stadiums to disappear, leaving the fans floating in midair.
After the update is live, please resave your stadium to correct the issue. Thank you.