PDF generator does not find logo after migration

I migrated SuiteCRM from a WAMP server that I’d set up to a Univention image and found that the company logo is missing from the quote PDFs since then. I’m just getting the red x

Initially, the system was still looking for the logo on the old server so I fixed that in the html source for the PDF template.

This did not work, so I uploaded a fresh logo to the server and created a fresh template to see where it would get the logo.

I could put the URL for the logo into my browser and see it but still not get it in the PDF output, even if it’s showing in the PDF template editor.

Any ideas?

The SuiteCRM version I’m working with is 7.10.9.

I’ve made sure that the DG library was installed on the server, this lead to no change.

I’m working around this at the moment by using the company name instead of the logo but that’a not a solution.