As Martiniano mentioned, disabling “Show Mouse Cursor” on the Player Controller seems to “fix” this for users that face this problem. Unfortunately, the mouse disappears. Using the “Set Show Mouse Cursor” node on “Get Player Controller” also triggers the bug.
I think Epic is aware of this. If you look at their “Cropout Sample Project” they work around this issue by registering Mouse Movement through the now deprecated Axis Mappings system. Almost everything else uses the new Enhanced Mapping system.
I am not sure why they have not fixed this since that project released but here is their own sample setup as a temporary workaround until fixed. Using the old system just for registering the mouse movement allows you to enable “Show Mouse Cursor” and trigger mouse movement events.
