I've been using DocHub for a few years now and one of the key benefits is that I can put a signature on top of another and keep the background one whole. It allows me to sign on top of the company signature. I have a hand-copy scan of my signature in a png file and it worked well for years.
Now the png file (with transparent background) is not working properly. It looks good in the Dochub web version of the files but when I create a pdf copy it changes the background to white and hides the company signature that is behind.