Question webtrees 2.0.19 thumbnail picture issue

Funny thing is that it previously existed on a small Debian 10 host which had the same imagick resource limits as Ubuntu 20.04 had before I changed it, as evidenced by the following imagick command:

identify -list resource
Resource limits:
Width: 16KP
Height: 16KP
List length: 18.446744EP
Area: 128MP
Memory: 256MiB
Map: 512MiB
Disk: 1GiB
File: 768
Thread: 8
Throttle: 0
Time: unlimited

Please check the Imagick library support JPEG and control panel Server information, Imagick, ImageMagick and supported formats. If JPEG is missing, then install it or adjust the resource limitations in the policy.xml file accordingly. Restarting Apache may be required after making changes.