Manual Thumbnail generation

[omroepmuseum]

Using Phoca Gallery 5.1.2 and Joomla 5.3.2:
When setting Options - tab Thumbnails - Enable Thumbnails Generation to No, manual Thumbnail Generation has following consequences: immediately one gets a message that the Thumbnails have been generated, however WITHOUT ever showing the generation progress screen.
In the Image list, there is no thumbnail shown anymore and the message "Enlarge Image" is shown. When one verifies the directory images/phocagallery/..., one sees that ALL the thumbnail-images in the "thumbs"-subdirectory have been deleted!
Setting Options - tab Thumbnails - Enable Thumbnails Generation to Yes cures the situation.
This looks like a bug to me!

Kind greetings,

Hendrik