Deleted participant on an existing invite still appears in "TO" list for other participants

Greetings,

I had deleted a participant in outlook calendar using the scheduling assistant tab and sent an update to only added or deleted invitees. However, much later when I updateD the invite to include some more test in the body of the email and hit send update to all, the deleted participant still shows up for all participants.  Please suggest how I can make sure the deleted participant is no longer in the invite. Thank you,