Hi Niklas
If it's any help, yes it is a new bug that only appeared with Windows 11 24H2.
As long as the ACP web browser is open then ACP's memory usage will increase by ~100MB per hour, or more depending on subtle differences between systems, until ACP uses all the available system memory available for a 32bit application, at which point ACP will crash.
How long an ACP run will progress before crashing will be variable, depending on whether you restart ACP before beginning a run (to reclaim the memory used so far), the time you begin the session, whether you leave the browser window open and the available memory you have on your system, etc.
Bob is looking for the cause now but he only became aware of the problem on Friday 31st January so this might take some time to resolve.
William.