Further to the previous post.... a couple of years later; a new machine (a lower resolution 1080p/HD 14" laptop); and a few new releases of BRU (currently, Ver 3.3.2.1) - I'm still having the same problem!
Windows have made some improvements to their scaling settings (UI), so I decided to go digging into it again.
I have found a workaround and some diagnostic information. I'm sharing these here that they might help with making a long-term fix.
- - -
On the new HD machine, I see 6 lines of files

https://ibb.co/n0TWNyb)
(Actually, that's with the BRU window not maximimised. If I snap the window to 'maximised', it goes down to
three lines of files visible: https://ibb.co/yV6Qhgn
-Selecting all combinations of settings under
Windows Compatibility Mode, made no improvements (a few of them stretched the text out horizontally, but nothing useful)
Under Windows Settings >Display
>Scale and layout >Change the size of text, apps and other items
-My Windows Scaling is set to the default:
'150% (recommended)'I see
6 lines of files in BRU (or 3 lines when the window is maximised).
-If I reduce the
scaling to 125%, I see a small improvement in BRU (
9 lines of files visible; or 6 when the window is maximised).
-But if I reduce the scaling to
100%, then I get a
step-change improvement, seeing 22 lines of fileshttps://ibb.co/6XFtCHP
(or 20 when maximised)https://ibb.co/GcdVV9q
So, it seems that it is, indeed a scaling issue. I hope that this helps y'all to figure-out a longer term solution. Maybe it's worth a note in the user manual incase other people are suffering in silence!
Of course, the F9 function helps, but it is also useful to see both the controls and the files concurrently; and I can't leave the PC's scaling at 100% as this makes most other apps illegible.
thanks
OS Windows 10 Home (currently ver 2003, but also on all previous versions of Windows 10.
14" HD Laptop