Hi all,

I'll try to explain, as clearly as I can, the problem we encountered on the 3.5.5, 3.5.6 and 3.5.9 versions (we did not test the others).
Ekos location/date/time are all correctly set (manually or using a GPSD extension) : South Eastern France 45 21 35.00 / 05 19 12.00, elevation 378.
Symptoms : Ekos meridian flip attempts seem to occur prematurely during the night, even though the mount is far from the north/south meridian.

These attempts occur at very high speed cycle (no 4mn delay between attempts) :
2022-07-20T17:17:40 Meridian flip completed.
2022-07-20T17:17:40 meridian flip failed, retrying in 4 minutes
2022-07-20T17:17:40 Meridian flip slew started...
2022-07-20T17:17:40 Meridian flip started.
2022-07-20T17:17:40 Meridian flip completed.
2022-07-20T17:17:40 meridian flip failed, retrying in 4 minutes
2022-07-20T17:17:40 Meridian flip slew started...
2022-07-20T17:17:40 Meridian flip started.
2022-07-20T17:17:40 Meridian flip completed.
2022-07-20T17:17:40 meridian flip failed, retrying in 4 minutes
2022-07-20T17:17:40 Meridian flip slew started...
2022-07-20T17:17:40 Meridian flip started.
2022-07-20T17:17:40 meridian flip failed, retrying in 4 minutes

The mount does not react to these attempts, since they occur far from the real N/S meridian.
But when I try to solve a target located right near this "virtual meridian", the slew attempts of the flip block the solver and Ekos does not manage to slew to this target, since DEC does not move at all (Slewing mount: RA increment = 85, DE increment = 0).

This "virtual meridian" line seems to rotate, centered to the North Pole, at the speed of earth rotation.
Currently, it seems to be aligned with the North-South meridian at 15:00 UTC, and 3:00 UTC (after a 180°/12hrs rotation).

I managed to detect this "virtual meridian" by doing GOTOs on the KStars map and noticed that the mount was not slewing straight to a near target, but going all the way to North Pole and back to the target.
You can notice this behavior in the attached video screen capture.

I don’t know if that’s the expected behavior, or if we forgot to set a specific parameter, but this seems to resonate with other threads of this forum.

Did anyone notice this and is there a way to workaround this issue ?
I’ll try to disable Ekos meridian flip and slice our scheduler session in 15mn sessions, forcing alignment (and a slew) each time, in order to trigger the mount meridian flip.

Hope this thread may help.

Sébastien