Calendar autocomplete not work

Hello! I have a calendar connected via DAVMail (Exchange Server 2019), everything works. But when I create an event in the calendar and start adding participants, autocomplete does not work (there is no list to choose from the address book). I have an LDAP address book configured for Global Address List (GAL) exchange. I also imported the address book to Cardbook via .vcf. How do I set up autocomplete in the calendar? (When writing an email, autocomplete works)