Window Group icons disappear after changing settings again

Steps to reproduce:

1. Go to a Window Group's Settings...
2. Assign ♥︎ ascii icon and save.
3. Go back to this Window Group's Settings...
4. Do nothing but click Save
5. Observe that after a pause the ♥︎ icon changes back to the default window icon.

Expected behavior:

♥︎ icon should still be assign to the Window Group.

Orion, OS version; hardware type:
MacOS 13.1, Orion 0.99.123.1-beta (WebKit 615.1.16.1)