We found that some of these users did not understand sentences that had negative contractions in them (negative contractions are words like ‘can’t’, ‘won’t’, ‘don’t’). They interpreted the sentence without inferring the ‘not’.
I have been in two minds about using contractions for a while. On the one hand, avoiding contractions does seem to reduce ambiguity. But at the same time it can make your writing seem stilted and overly-formal.
As always with writing style, there will be no true answer, and the right way forward will depend on the circumstances. But if in doubt, it is worth considering avoiding contractions.