I know that the topic of the meridian flip has been discussed countless times.
I have tried it with the simulator and once I thought I understood it, I have tried it with the mount, a celestron AVX.
I used a profile of simulators except for the AVX.

Mi AVX has mechanical traking limits of -05deg west and east
In EKOS I set:
max HA 0.27 h
Flip if HA > 0.13 h

(by the way, should not be more friendly and less mentally demanding to be able to set these parameters in minutes (or alternatively hh:mm format) instead of decimal hours?)



Things seems to go well, with the count down going on but when flip has to happen, the countdown is replaced by:

Meridian flip planned...

It stays like this with no other information until limits are reached and the telescope stops tracking...
An nothing happens.

What am I failing at?

Oh no sorry to hear you're facing similar challenges. Yes that same thing has been happening for me (both it saying a flip has happened but then nothing actually having happened, and what you describe as "Meridian flip planned..." & then nothing). Will follow this thread with interest.

@geehalel has been v helpful in the other thread - as he says, it seems like a software confab is perhaps called for among INDI developers!