Thought I’d post an update on the problem that I started this post about. Just in case anybody else runs into this. The accepted solution was given by @DaveR – clear IE cache. But today, by chance I noticed another reason that this was happening. Not sure if it’s just my machine, or if it’s still associated with the cache, or what, but if you watch the screencast I’ve attached, notice that when my cursor is above the dropdown search-suggestions dialog, the same thing starts happening, where I can’t type out a word in full. Then when I move the cursor outside of that dropdown area, I can type things out like normal.