Noticed a couple of things in the recent Alfred update (v3.6.2 [922] on macOS 10.13.5) that results in the input being overwritten, which I don't believe was the behaviour previously and seems like a bug to me.
1. Typing just a space results in it being replaced with a single quotation mark '
2. Typing '===' results in it being replaced with '=0'
1 is a very common issue for me as I always start with a space when I want to do a web search.
2 came about as I sometimes use Alfred as a quick scratch pad and teaching tool via the Large Type feature (I was explaining strict comparison in JS).