FVWM: font problem in migration 2.6.8 to 2.7.0

As I said yesterday in another post

> I have just updated a laptop from (X)ubuntu 22.04 to 24.04 and this 
> resulted in an update of fvwm from 2.6.8 to 2.7.0

I am experiencing a problem with the fonts of the buttons of a 
FvwmButtons.

My configuration (described, with screenshots and sample .fvwmrc in
http://sax.iasf-milano.inaf.it/~lucio/WWW/Opinions/window.html#lap)
has a button box called MyBox in the top-right side if the screen.

As it works on my 20.04 desktop and worked on the 22.04 laptop, it has 
buttons (the ones labelled "task bar on/off", the date, "1/2H/2V/2X", 
"Pager on/off" etc.). These buttons appear in a bold font.

Now on Ubuntu 24/04 with fvwm 2.7.0 these buttons appear empty. They do 
work (when clicked). I see no errors in .xsession-errors.

If I remove (comment out) the *MyBox: Font line in .fvwm2rc (so that it 
uses the default font), the button text appears, in a smaller and not bold 
font.

BTW, xlsfonts shows the laptop has all the same fonts than the 20.04 
desktop (plus others).

The font definitions (inherited from previous installations, I suspect 
some of them might be emulated) are such that *MyBox: Font is the same as 
*MyTaskBar: Font  and the latter (another FvwmButton containing an 
FvwmIconMan) displays the bold font correctly

What can be the cause of all this, and is there a way out ?


-- 
Cosi' per li gran savi si confessa / Che la Fenice muore e poi rinasce, /
Quando al cinquecentesimo anno appressa. (Dante, Inferno, XXIV, 106-108)
Thus the great wise testify / That the Phoenix dies and is born again, /
When the five-hundredth year gets close.