Meridian flip sequence

[gcs]

I have been using the sequencer for years and it has worked well.
But this is the first time I have tried to include a block to automatically do a meridian flip, then carry on.
The logic of this seems straightforward.
The start guiding line could be placed in a couple of different places, other than what I tried here.
I have everything running before I get to this step. Target, tracking, guiding, camera settings, etc.
But when it gets to the conditional step monitoring the meridian, it fails when it tries to start guiding again.
This is with an HEQ5 mount connected and controlled using ASCOM.
Got any idea why it fails at the start guiding step?

SEQUENCE
SAVE MOUNT COORDINATES
LOOP 4 TIMES
PRESERVE CAMERA SETTINGS
FOCUSER CONNECT
SET EXPOSURE TO 1
SET GAIN TO 350
AUTOFOCUS OFFSET -50 TO 50 STEP COUNT 9 BACKLASH 100
END PRESERVE
PERIODIC "Meridian Handling Steps" WHEN WITHIN 0 MINUTES OF MERIDIAN
GUIDING STOP
PRESERVE CAMERA SETTINGS
MOUNT GOTOTARGET
DELAY 5
SET EXPOSURE TO 1
SET GAIN TO 350
MOUNT SOLVEANDSYNC
END PRESERVE
END PERIODIC
GUIDING START **** It's failing here ****
GUIDING DITHER EVERY 4 FRAMES
CAPTURE 30 FRAMES REQUIREGUIDING True
END LOOP
END SEQUENCE