Mail search does not work - Spotlight does

Since some month I can't search in my emails anymore. This problem existed on Ventura and now on Sonoma.

The strange thing is that spotlight does find the emails when i'm searching there. Only the search within Mail does not work.

Things i tried:

• rebuild mail index
• delete all inboxes and added a single inbox
• restart
• closing mail app multiple times
• removed the whole MailData folder
• toggled spotlight settings for Mail

I don't know what to do anymore. This probably exists for months! One thing i noticed:

When i reset the Mail app and its downloading all the messages again, the search does seem to work for emails that were just downloaded. But after that the search results are again empty...

I tried to find the related logs in the console for the mail application. Here are the statement that are probably related to a search:

default	09:32:02.979964+0200	Mail	SearchField was updated with userString: "Ha..."<3 chars, hash=78bc> suggestion: <private> isSuggestionEmpty: NO
default	09:32:02.979995+0200	Mail	Cancelling search #88, text:'<private>', suggestion: '<private>'. Now 0 active operation(s), 1 cancelled operation(s).
default	09:32:02.980026+0200	Mail	[0x60000152ce60 Ranked Suggestions] cancelling query:<private>
error	09:32:02.980093+0200	Mail	Failed to generate suggestions <private>
default	09:32:02.980109+0200	Mail	Search #88 completed async suggester 'Ranked'.
default	09:32:02.980123+0200	Mail	[0x60000152ce60 Ranked Suggestions] cancelling query:(null)
default	09:32:02.980133+0200	Mail	Start search in all mailboxes without mailbox filter query
default	09:32:02.980139+0200	Mail	Search #88 did complete suggester 'Ranked'. All suggesters done.
default	09:32:02.980940+0200	Mail	Cancelled search #88 did complete all suggesters.
default	09:32:02.981018+0200	Mail	Search #88 did complete, but it’s cancelled.
default	09:32:02.981106+0200	Mail	Starting search #89, text '<private>', suggestion: '<private>', 45532192 suggester(s): 'Recent, Ranked, Documents, Links'. Now 1 active operation(s), 0 cancelled operation(s).
default	09:32:02.981312+0200	Mail	[instant answers] Enabling instant answers in csTopHits query context
default	09:32:02.981362+0200	Mail	Setting customFieldSpecifications: <private> on csContext
default	09:32:02.982526+0200	Mail	Setting top hits query with searchString: <private> and csContext: <private> with suggestion: <private>
default	09:32:02.982554+0200	Mail	[0x60000152ce60 Ranked Suggestions] starting query:<private> searchString:<private> filter:<private>
default	09:32:02.984560+0200	Mail	qid=735 - Finished

Does anybody have an idea what i can do to fix this?