FVWM: FvwmIconMan does not update new windows (?)

Hi all,

I recently update to Ubuntu 20.04 and fvwm 2.6. I am quite happy but
for a problem with FvwmIconMan: it does not update when new windows
are opened or closed.

When StartFunction is called, I may see one of two things:

  -- FvwmIconMan shows all startup windows (maybe they are already
  created when FvwmIconMan starts and it sees them?)

  -- FvwmIconMan shows only itself (maybe FvwmIconMan starts before
  other windows and later it does not see them?)

In any case, when new windows are created FvwmIconMan does not show
them, no matter what.

For example, these applications may be opened and do not show on
IconMan: xterm, rxvt, xclock, xeyes, xdvi, stterm and others.

Quite surprisingly, xfig shows up. Why?

My configuration for FvwmIconMan is quite simple and worked
previously, but maybe I do not see some that I should see?

  Style FvwmIconMan   !Title, Sticky, WindowListSkip, NakedTransient

  *FvwmIconMan: Action Mouse 0 N SendCommand Iconify -1, Focus
  *FvwmIconMan: Action Mouse 1 N SendCommand Iconify
  *FvwmIconMan: Action Mouse 2 N SendCommand Module "FvwmIdent" FvwmIdent
  *FvwmIconMan: ManagerGeometry 1x0+0-0
  *FvwmIconMan: MaxButtonWidth 100
  *FvwmIconMan: UseWinList true
  (color config omitted) 

I was unable to find something similar on the web, so I ask for advice
and wisdom. Please send any advice to [email protected] !

best regards and happy new year,

joao oliveira