JPG images with bad quality after kirby update

after updating from kirby v to kirby v jpeg thumb images have very bad quality on the website and within panel image preview.

this strangely only happens on the webserver (not with the local dev project). at the same time Php version was also changed to 8.1

are there any known issues with jpeg compression with one of the newer kirby versions?

did you increase the kirby version number in composer.json and run composer install after dropping the new kirby-folder?

did you clear the β€˜media’-folder?

here is what i did on the local project:

composer update

the require statement in composer.json reads like this

"getkirby/cms": "^3.9"

since composer is not used on the webserver, i deleted the kirby and media folders there. then copied the kirby folder from the local project to the webserver.

i was trying to solve this within the configuration setting quality for thumbs, but no success unfortunately.

maybe old gd or no im (imagick) version.