capture: can't change exposure time after first exposure - by: alacant

Hi everyone
Canon700d
Set the exposure to 1.0s in capture and hit preview. The length of the exposure is now fixed at 1.0s in both capture and align no matter what exposure is set.
Any ideas?
TIA,
Steve
log: drive.google.com/open?id=1Bkh9NPZRIGLykv8gqwB_8vgpPzpvFxIg