Turns out when I remove the --downsample 6 it works. This is set from the astrometry settings in ekos where it's set to Auto which works fine when Aligning.
Not sure how to handle this - if I turn off downsampling then my file solving will work for 'load and slew' but I'll have slowed down the working plate solving in kstars when I'm doing alignment. Any suggestions why file solving would be different here?
Downsample 6 may just be too aggressive and is crushing your stars. Try a lower value.
INDI/KStars on Raspberry Pi 4, 4gb
Raspbian Buster with AstroPi3 script configuration
Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG/ASI120mm @280mm Guide Scope
Waveshare Stepper Motor Board - DIY Focuser
Adafruit GPS Module
Generic Bluetooth Joystick.
Startech 7 port powered USB Hub.