Prevent from auto-updating to 6.0.0

Our own software has been using PDF Creator 5.3.2 to create PDF's.
Since 6.0.0 is out, our PDFcreators keep auto-updating to 6.0.0 which does not work with our software (yet)! We don't OK an update, it just does it by itself, on all our machines.

We've tried uninstalling 6.0.0 and re-installing earlier versions but a couple of hours later, it is back to 6.0.0 again. Again, all without our approval to update and without any notice.

We've tried setting the update interval to Never in the registry, etc. but nothing seems to prevent the updating.

We've tried support but they keep getting back to "please set the update interval" to month.

Who can help us with a solution? It's greatly appreciated!

What registry settings are you using?
I have never heard of it.

I'm using PDFCreator free Version 5.3.3 on Windows 11 Pro 24H2 and in my experience with PDFCreator it never updated itself without my consent.

Never happened also on the dozens Windows 10 Pro PCs I take care of.

In Settings there isn't an option for auto-update, there is an option to [Check for updates:] Daily, Weekly, Monthly.

If I click on [Check now] it asks to install the new Version 6.0.1 but let me choose between these options:
[Install] [Ask later] [Skip version]

Very strange what's happening to you.

Hi Gianni, thanks for your reply.
Yes very strange. And it's on all machines. WIndows 10 and 11 combined. I've told it to skip the new version on installation and still it updates.

Hi Gianni, FYI: We’ve found the problem. A new version of our virusscanner updates third party software when possible! This is the cause of the auto updates.