The code is valid for another full minute, typically, after it's rotated for a new one. This isn't much of a valid reason to prefer notification-based 2FA.
It is not obvious to everyone that a code may still be valid after its gone from your screen. You cannot use the first 3 digits from one code and the last 3 from another, so you start over when you don't have all 6 digits before the code changes on you.
Different strokes for different folks. I care to have folks be successful.
This sounds like an education issue; if you were to say "wait until the code changes, then go for it", they have thirty seconds to read and type six digits.
If this still doesn't work for them, perhaps a hardware token they can tap might be a better solution.
TBF the code still being valid doesn’t help much if the user hasn’t memorized and/or finished typing it all.
Sitting next to some family members, they really can’t remember more than one or two letters at a time, and will peck and hunt each of it. Except if they were typing the last digit, the code disappearing from screen is basically the end of it for them.
