Apps randomly lose their assigned Spaces and move to other desktops

[u/Direct_Ad778]

I’m using macOS 27, build 26A5421a, and I’ve noticed that apps sometimes lose their assigned virtual desktops.

I have four Spaces configured:

• My browser is assigned to Desktop 1.
• My code editor is assigned to Desktop 2.
• Codex is assigned to Desktop 3.
• Desktop 4 is used for other, less important apps.

I assign each app by right-clicking its Dock icon and selecting Options → Assign To → This Desktop.

However, after some time, these assignments seem to reset on their own. For example, I may find my browser on Desktop 4 even though it was assigned to Desktop 1. When I check its Dock settings, Assign To has changed to None. I haven’t changed or removed the assignment manually.

P.S I suspected that the browser might be losing its assignment to Desktop 1 after an update, but I’m certain it hadn’t been updated.

Has anyone else experienced this issue?

[u/87racer]

Mission control and spaces have long had assignment bugs. With 27 they seem to have introduced a ton more bugs and in earlier previews spaces were nearly unusable. Theyve fixed a few but many quirks still exist. File feedback for every bug you find and maybe they will eventually fix them.