bug#32207: 26.1; can't set window position with emacs 26.3

[emacs]

>>    emacs -Q --eval "(setq initial-frame-alist '((width . 40) (height . 20) 
>> (left . 400) (top . 400)))"
>> Emacs 26 works perfectly! even with off-screen positions.
> Does that work _without_ specifying 'user-position'?

Yes, though I should qualify the "perfectly!" above.
- there is an initial frame that seems to be placed by fvwm,
  at a position of the window manager's choice
- the initial frame is then moves to the position specified
  in the command line.
- the moves comes almost immediately after the intial
  placement, resulting in a flashing effect.

> Does -g work when you specify a non-nil 'user-position' in
> your X resources file?

Can't get emacs 25 or 26 to obey resources.

I've tried by editing my files, xrdb'ing, and running
  emacs -Q --xrm='emacs.geometry=WxH'
the initial frame always comes up as 79x35

-- Henrique