How to make the scrollbar thumb always appear

Apologies if this has been posted before, I tried looking for similar issues but couldn't find this exact issue*.

How do I make the scrollbar thumb (the bit you click on the drag the scrollbar around) always appear in Adobe Acrobat on Windows 11?

Right now the thumb only appears when you mouse over the scrollbar. This is a major usability issue, especially for long documents, as I have to guess where the thumb is and then make a corrective mouse movement when I inevitably get it wrong. In Acrobat on previous Windows versions and in every other app on Windows 11, a skinny scollbar thumb is always shown so that I can mouse directly to it and the thumb gets big when you mouse over it. In Adobe Acrobat on Windows 11, no thumb is shown by default and the skinny thumb only appears when you mouse over the scrollbar.

The following screen captures demonstrate the issue.

In the first screen capture, I am attempting to scroll a long document in Adobe Acrobat. Notice how the scrollbar thumb is not visible, and I have to make two mouse movements to grab it to scroll:

In the second, I am attempting to scroll a different application. Notice how the scrollbar thumb is always visible so I am able to mouse directly to it:

Like I say, this appears to be a Windows 11 specific issue as I only noticed it after upgrading from Windows 10. Other apps don't have the issue, so it appears to be Acrobat specific thing.

How do I make the scrollbar thumb always appear?

*I found a lot to do with the scrollbar not appearing at all, but that's not the issue I'm having, those issues appear to be Mac specific, and the suggested resolutions refer to options that don't exist on my Acrobat.