Autocomplete doesn't show recent people

Hello,

Recently my outlook autocomplete changed from this:

to this:

just a grey stack of names and e-mailadresses

This is annoying as it will show every e-mail adress with that letter, also very old ones I haven't used in ages. Also the 'X' doesn't appear next to the names anymore so I can't delete them from the list.

Does anyone know how to revert it back to the first example of my post?