After a colleague of mine migrated Exchange for a customer from Exchange on a small business server to Exchange 2016 the dates are messed up when searching. When a user just browses his or her email on their phone, all dates are correct. But when they make a search the date of the search time shows up instead of the actual sent/received time. The mails are also not sorted in the correct order because of this.
This does not appear to happen on a newly created account, but only with the accounts that where migrated from the old server. I've also tested setting up one of the affected accounts on my own iPhone, and experience the same problem. But only for that account. No problems with my own Exchange email that resides on a different server.
When searching in the mailbox through Outlook (both for Mac and Windows) there are no problems, and searching in OWA also works like normal.
Do you have any suggestions for me?
EDIT: I've also inspected the mail headers of some of the emails via OWA, and I'm not finding anything weird.