Category is being excluded by plugin

Hi
In the notification selection, there is a list of categories which you may select also for including/excluding categories. I’ve selected all categories however, there are 2 categories which are excluded all the time, no matter even if i select them and save the changes. they go back to the deselected status. Is there a limit on the number of categories? please advise accordingly.

https://www.ads-software.com/plugins/email-subscribers/