Sort @ mentions list by recent activity after typing first part of username

Very frequently I type @ and a letter, it shows the right person and I hit tab, then it auto-completes the wrong person. I think this is because the list of users loads the entire list one split second before I hit tab, but also because when that list is loaded it is a list of all the users starting with that letter in the entire community alphabetically.

I think what should happen is when you type @ and then start typing, it should only filter the list of recently chatted members by the letters you're typing, until that list is empty. Only when the list of recently chatted users is empty should it switch to searching all members in the server. Either that, or the user highlighted in the filtered-by-letters list should just always be the most recently active user the current letters would apply to, instead of that list being sorted alphabetically.

I can very consistently reproduce this by typing @ and then a letter, if you do it you will see it show one list of people filtered by that letter, and then very quickly afterwards it loads a different list of people. That intermediate list throws me off constantly, and I see a lot of people in my community pinging the wrong person so I assume I am not alone.