DWG to PDF not supported anymore ?

Hello,

One of our customers was using Acrobat to convert a lot of DWG files to PDF without having to run Autocad. Then one day, it stopped working.

So I'm the one who has to solve this problem.
I installed the latest version of Acrobat Pro DC on both my machine and on a virtual machine to make sure it was not related to a bad installation/conflicts. For both I get the same error message when I want to convert : "Conversion of this file format to pdf is not supported on the 64-bit version"

Here's the step : Tools -> Create PDF -> Create (after loading a DWG files)
And i get the same error if i try to open a DWG to PDF through windows explorer or when i try to combine several DWG.

Also, when I'm in Create PDF and I go to Advanced Settings and then click on Configuration Preferences I get the following error:

This functionality is currently unavailable as Autodesk filters component of Adobe Acrobat is not installed. Please Install this component using Adobe Acrobat installer to access this feature.

But it seems to me that this is an old message since there is no more Adobe Acrobat Installer (am I wrong?)

The problem is that an official Adobe page states that it's installed by default here:
https://helpx.adobe.com/acrobat/using/creating-pdfs-pdfmaker-windows.html

Convert Autocad files when Autocad is not installed

So I searched on the web to see solutions, some say that you need Autocad now, others that it just does not work anymore, others that it should work.
So I downloaded the latest version of Autocad, it didn't work.
Then I saw that PDFMaker was only compatible until Autocad 2019 (according to an official Adobe page https://helpx.adobe.com/fr/acrobat/kb/compatible-web-browsers-pdfmaker-applications.html)

So I downloaded the Autocad 2019 version.
It works, but the problem is that it goes through Autocad (Acrobat DC Pro opens Autocad and each DWG file one by one and converts them one by one)
It takes much more time than before.
And I still get the same error when I go to Configuration Preferences in Advenced Settings.

So I have several questions:

How do I download old versions of Acrobat Reader? I've looked and I can't find anything official for that.
Should the DWG to PDF conversion be possible without opening Autocad in the latest versions?
And more generally I'm obviously interested in any solutions to this problem.

Thank you