I was having the exact same problem today.
I have the latest free version (R114 32bit).
You could even put in an angle of 269.9 or 270.1 and it would go 'UP'. But if you wanted 270, it zips to the left.
So I wanted to submit a CAPX file and reduced the code so it was more manageable.
I was able to recreate the problem fine. Then by accident I closed Construct.
When I reopened it, my sample worked properly and my OLD project worked properly, with an angle of 270 going 'UP'.
Could this shed light on the issue?
If it happens again, I will do my best to recreate it and see if restarting it fixes it.