I am using a Sesto Senso focuser.
I am able to use the focus module to manually focus and I am getting great results. 
Now I would like to let the Auto focus do the work but it takes a frame, moves the focuser and never goes any further. It's like it does not know that the focuser has finished moving.
Before I start debugging I was wondering is anyone has had a similar experience, maybe its just one setting I have wrong?

Rishi,

I don't know if this is your issue, but I noticed a similar effect with the focuser I use, the RainbowAstro RSF www.rainbowastro.com/rsf-2/. I fixed that issue in its Indi driver a while back. I found that there was sort-of a rounding error, where the focuser would sometimes move to within 1 step of the target position (an int) and stop there, but the Indi driver would wait (forever) until an exact match to the target position. I fixed it by creating a target-position tolerance in the driver--the driver considered the move "done" if its position was within the tolerance (of 1 in my case) of the target position. It works fine now. Perhaps the same thing is happening for you?

Here's a pointer to the code allowing target-position tolerance in the RSF indi driver:
github.com/indilib/indi/blob/master/driv.../rainbowRSF.cpp#L253

Hy

Just checked the code an it works in a different way. It's looks for a finished response from the focuser:
if (!strcmp(res, "GTok!"))
return true;

I assume this is not happening. I should switch on the logging if I want to have a better idea what is happening.
It's finally clear and I am imaging, I always find it difficult to experiment on clear nights!

This is what I see in the logs:
[2021-11-08T21:24:22.383 CET DEBG ][ org.kde.kstars.ekos.focus] - Starting focus with box size: 32 Subframe: yes Autostar: yes Full frame: no [ 0 %, 100 %] Step Size: 100 Threshold: 150 Gaussian Sigma: 1.5 Gaussian Kernel size: 5 Multi row average: 7 Tolerance: 3 Frames: 1 Maximum Travel: 20000
[2021-11-08T21:24:22.388 CET INFO ][ org.kde.kstars.ekos.focus] - "Autofocus in progress..."
[2021-11-08T21:24:22.391 CET DEBG ][ org.kde.kstars.ekos.focus] - State: "In Progress"
[2021-11-08T21:24:22.394 CET INFO ][ org.kde.kstars.ekos.focus] - "Capturing image..."
[2021-11-08T21:24:24.205 CET DEBG ][ org.kde.kstars.indi] - processBLOB() mode 1
[2021-11-08T21:24:24.242 CET INFO ][ org.kde.kstars.ekos.focus] - "Image received."
[2021-11-08T21:24:24.250 CET INFO ][ org.kde.kstars.ekos.focus] - "Detecting sources..."
[2021-11-08T21:24:24.289 CET INFO ][ org.kde.kstars.ekos.focus] - "Detection complete."
[2021-11-08T21:24:24.293 CET DEBG ][ org.kde.kstars.ekos.focus] - Focus newFITS # 1 : Current HFR 1.64506 Num stars 1
[2021-11-08T21:24:24.327 CET DEBG ][ org.kde.kstars.ekos.focus] - ========================================
[2021-11-08T21:24:24.329 CET DEBG ][ org.kde.kstars.ekos.focus] - Current HFR: 1.64506 Current Position: 54490
[2021-11-08T21:24:24.331 CET DEBG ][ org.kde.kstars.ekos.focus] - Last minHFR: 1.24361 Last MinHFR Pos: 54390
[2021-11-08T21:24:24.332 CET DEBG ][ org.kde.kstars.ekos.focus] - Delta: "40.1" %
[2021-11-08T21:24:24.333 CET DEBG ][ org.kde.kstars.ekos.focus] - ========================================
[2021-11-08T21:24:24.335 CET INFO ][ org.kde.kstars.ekos.focus] - "FITS received. HFR 1.65 @ 54490. Delta (40.1%)"
[2021-11-08T21:24:24.368 CET DEBG ][ org.kde.kstars.ekos.focus] - Focus "outward" ( 100 )
[2021-11-08T21:24:24.375 CET INFO ][ org.kde.kstars.ekos.focus] - "Focusing outward by 100 steps..."
[2021-11-08T21:24:24.378 CET DEBG ][ org.kde.kstars.indi] - Sesto Senso : "[DEBUG] CMD <#GT54590!> "
[2021-11-08T21:24:24.381 CET INFO ][ org.kde.kstars.indi] - Sesto Senso : "[INFO] Focuser is moving to position 54590 "

No indication that the movement is complete.

When I look at a manual focus I see something odd too:

[2021-11-08T21:38:54.768 CET DEBG ][     org.kde.kstars.ekos.focus] - Focus  "inward"  ( 1000 )
[2021-11-08T21:38:54.769 CET INFO ][     org.kde.kstars.ekos.focus] - "Focusing inward by 1000 steps..."
[2021-11-08T21:38:54.838 CET DEBG ][           org.kde.kstars.indi] - Sesto Senso : "[DEBUG] CMD <#GT53390!> "
[2021-11-08T21:38:54.844 CET INFO ][           org.kde.kstars.indi] - Sesto Senso :  "[INFO] Focuser is moving to position 53390 "
[2021-11-08T21:38:54.866 CET DEBG ][     org.kde.kstars.ekos.focus] - Abs Focuser position changed to  52790  (state =  2 )

The changed position does not match the instruction.