No thumbnails in MiniFrontpage

I am testing minifrontpage at this link, merlin-industrial.com/leasing
I cannot get any images to display.
Can you confirm that it will work in the Pro version, as I am trying to get something to work to show recently modified articles?
Just a bit more info.We did try the latestnews+ prior to this, and this would only show the default image that we had selected.
The thumbnail images are there, as per the attachment, but from the default image set above.I have cleared the folder as per something mentioned in the forum, though they keep coming back.
Are there any PHP extensions that need to be activated and I am assuming that the image is from the intro text?
Regards
Bob

I have attached an image of the folder and have just cleared them again. Note all the images are the same file size, so all the same default image. All the latest articles have .jpg intro images.
We have also asked the server support team to let me know if any PHP extensions could be involved that need to be enabled.

Just checked and we have php80-php-gd installed and enabled. I turned off the default image and now just the text.

I have installed the Random Image module and that is also not working, so it would appear to be a server problem and not the module. Have asked the server support to check as we have some extensions disabled for security disable_functions = show_source, system, shell_exec, passthru, exec, phpinfo, popen, proc_open