I was having problems with Gigapixel AI. It took very, very long time for each optimization
The standard processing time is between 1:30 and 2:00 minutes. But when the issue occurs it may take up to 20 minutes.
I have figured out that this happens when Photoshop is active, when I work also on the Photoshop.
Photoshop the newest version, production version.
The problem is solved when Photoshop is not an active app, but strangely, also when using Photoshop Beta the issue does not occur.
This is weird, but not a big problem.