[sorry for the delay, i don't see my reply to your last message posted, grrr. I'll reconstruct it]
( this is not a showstopper, but several times a week in support roles, we guide our clients thru similar)
102.0.12 (STANDARD) CentOS v7.9.2009
[specific email account]
MANAGE EMAIL ACCOUNTS
Free up Email Storage

Clarification/correction: the following is not a dropdown, but rather autofill choices. Perhaps therein is the predicament (it might be populating suggestions from an unrelated similarly named input field somewhere)
So assuming that is the case, then the suggestion is to have a tooltip popup of syntax options more than just. ("savedbefore" is not obvious)
It takes a bit of drilling down in the dovecot links to find:

So assuming that is the case, then the suggestion is to have a tooltip popup of syntax options more than just. ("savedbefore" is not obvious)
It takes a bit of drilling down & scrolling down in the dovecot links to find which are not obvious that this is syntax for this usage.
Maybe make the link for help point directly (and only) to
Tools/Doveadm/SearchQuery - Dovecot Wiki#section_date_specification
Thank you!