Thanks for reporting the issue, turns out it was a very old bug I was never able to figure out.
In the future if you find any more problems please report them in our bug tracker github.com/Scirra/Construct-3-bugs/issues
It's a little bit more work, but it is more likely we can see it and do something about it. This time it worked fine to post the problem in the forum, but more often than not these forum reports get lost and forgotten.