Running into an issue on an SharePoint Online Form where typing the first three letters of a name in the people picker and it just spins. Then typing more after it spins just causes it to spin with no results. If I clear the search and type a username it finds that relatively quick.
There is another issue where if the people picker field is required by the list and the field loses focus it will mark the field as missing with an error (which is fine). Then when the field is re-focused and someone is picked from the people picker it still shows up in error. Until the field is cleared and another search is completed. If the field isn't cleared it will spin. Then if the field is cleared loses focus and refocuses.