I have had a similar issue, it stemmed from the polar alignment assistant. If I run a refresh of 1.000 second exposures, or another increment that is a default on the camera's dial, while adjusting my polar alignment, I noticed that, that value (1 Second, 2 seconds etc.) if it is a factory default timer increment on the camera's wheel it will stay that way after completing the polar and alignment. Then I have to manually scroll the camera's dial to BULB, as it will be stuck on 1 sec, or 2 etc. Now if I do a refresh with an exposure of say 6 seconds during the polar alignment, the camera will stay in BULB as 6 seconds is not an exposure option on my Canon T6 (1300D). It was frustrating at first, but after I figured out the correlations, I just remind myself to set the refresh exposure to 6 seconds, or remind myself to check the exposure timer setting on the camera, before setting up a capture sequence. Sorry if that doesn't seem too clear but its the best way I can describe it for now.

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