[Startrek (Martin)]

Don’t know if anyone can offer an explanation on the following issue -
I have been guiding successfully now for a few months usually around 1 to 1.5 arc sec error which has enabled me to take up to 5 minute exposures and tac sharp stars
The issue is when I connect and start looping exposures sometimes it takes 10 seconds for the camera to lock on ready for calibration and guiding and other times quite often looping drags on beyond the preset 40 seconds and I get an error display
This has happened on the same night a number of times with clear skies and not a cloud in sight
Guide Scope - Orion 50mm mini with helical focuser
Guide camera - ZWO ASI 120MM
Main scope - 6” f6 newt on a HEQ5 mount
PHD2 version 2.6.5
Camera exposure duration 2 seconds
Brain settings camera
Noise reduction 2x2 mean
Auto exposure 1 to 5 sec
Target SNR 15
Saturation via star profile
Pixel size 3.75
Camera gain 95
Binning 1
Disconnect 40 sec
Brain settings guiding
Search region 15 pixels
Star Mass detection enable tolerance 60
Min star HFD 0
Focal length 162mm
Calibration step 700ms
Use DEC compensation
Auto restore calibration unchecked
Always scale, Fast recentre, enable mount guide output all checked
Note : I have no issue at all connecting PHD2 to mount ( EQMOD HEQ5/6 Ascom ) and to my ZWO camera
Getting past the continuous looping is the problem , once the camera is taking exposures the guide button is green and away I go no issue

Any advice or tips would be greatly appreciated
Thanks