I have a similar issue with my CEM60. I use KStars V3.6 and INDI V 1.9.7 on Raspberry Pi. The driver for the CEM60 is the one specific to the mount.
The calibration always fails.
Hopefully PHD2 works fine and ufffff I can shoot the stars. Otherwise that won't be possible.
The guiding rates are well defined in the mount via the handpad.
There is no track of the guiding rate values in the xml configure file of the CEM60.
So I wonder that those values are read from the mount if not there is no track of those values other than in tab of the mount.
I wonder that values of those guiding rates are either equal to zero either crushed by some memory leak.
The fact is that at the moment guiding with CEM60 and Ekos is not usable.
Just thought that I would contribute my experiences with a similar problem with my iOptron CEM40. Initially I noticed a periodic error in guiding with a deterioration every 750 secs. I suspected the belts so tightened up the tension but the problem persisted. Next the calibration started to fail with similar issues to those described here. I could still get away with guiding but later the calibration failure was what forced me to take the belts off and closely inspect them. They looked perfect from outside but on inspection some of the teeth were flattened and the fibres of the reinforcing were starting to fray. The mount is about 18 month old with medium use and no pier strikes etc.
I sourced a replacement belt locally (not an ioptron one but these belts are standard ones) and everything now works perfectly.
I also did firmware updates when the problems started but the only thing that made a difference was replacing the belt. So I think that Jasem's comment about considering hardware/mechanical causes is appropriate.
I was suprised that the belts would need replacing after such a short time but maybe they are a weak point in these mounts and will need replacing regularly. The replacement process is pretty simple and are illustrated in pdfs available on request from ioptron and I think you can find them though some of the US and UK astronomy forums.
As I can't solve the problem of calibration. I took decision to use PhD2 instead of internal guider. I will wait for some version that could fix the problem.
Until there I will check the evolution of Ekos/INDI each time the sky allows me to do.
But I am quite sure that there is something broken somewhere in the process of calibration for ioptron mounts in Ekos.
I believe that if PHD2 works fine that might means that the driver is not responsible of the problem.
I can't make test the last two weeks, first I have to make captures (with V3.5.9) and then the second week was horrible, cloudy and rainy. I came back home, the wethear is bad also. I update to V3.6.1. I try to make a test as soon as possible.
Is it on a iOptron mount ?
If yes symptoms are the same for me.
Have you tried to use PHD2 to see if it is a mount/mount driver/Indi/Ekos problem.
If calibration works with PHD2 Indi and mount/mount driver are out of the question.
But I didn't check yet last updates.
no i have a classical NEQ6 mount.
Guide module worked correctly before updates 3.6.1 and 1.9.8
Quite many things changed in this last update so, i was wondering if some other set up was necessary...hidden somewhere else in kstars...
I replied on your post thinking the problem you have too is not directly related to the mount but more to the Guide Module
I didn't tried yet PHD2, but indeed need to install it, could help to analyse the problem.