Help needed to understand problems in STK with Octave 6.1.0

Hi all,

There are many failing tests in STK with Octave 6.1, as reported in [1] 
for Windows and (downstream) in [2] for Debian.

After some investigations, it seems to me that these failures are all 
(or almost all ?) related to OOP-related regressions in Octave 6.1.0.

One of these regressions is described in [3, 4]: the dispatch mechanism 
is broken when function handles are involved.

But there are other types of failures (type b and c in Comment #2 of 
[1]) that I do not understand at all.  Some help would be much welcome.

@++
Julien


[1] https://savannah.gnu.org/bugs/?59340 
<https://savannah.gnu.org/bugs/?59340>

[2] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=976206 
<https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=976206>

[3] https://savannah.gnu.org/bugs/?59631 
<https://savannah.gnu.org/bugs/?59631>

[4] https://savannah.gnu.org/bugs/?59617 
<https://savannah.gnu.org/bugs/?59617>