Hey @Bouncy Sheep!
The update messed a bit with highlights and a fix being worked on. As you noticed when you reset the highlights it highlights your username by default, it's a new feature to make the extension more user-friendly to newcomers.
Anyway, I just wanted to let you know that the reason why when you imported your previous settings it stopped working is because they overwrite everything. I suggest exporting your settings now so when you import them again in the future it'll work from the get-go.
Props to you for experimenting by yourself before saying that it didn't work, too few people do this, so thank you!