Problem with the search box (returning only limited results)

If I use the search in an imap account the results are not complete.
I opted to search into the mail text: (Textteil)
It seems that it finds old mails but not new ones.
If I search for “Sendungsstatus” I can find DHL mails which are 5 months old. But newer Mails with this string are not listed.
I also activated server search and I also selected that the mails are downloaded for offline use.

emclient version is 9.2.2157 5b49542

A server search has a limit on how many results it returns, so even if there are more messages that match you won’t see them. Can you untick that option and try the search again.

I unticked server search and not a single result was showing up

You are using current folder and its subfolders. Maybe there aren’t any actual matches in the specified folders.

If you change that to All Folders, what is the result?

now it says that results may not complet. Even if I confirm to download all mails:

Result is still old mails are shown. Could it be that the search is case sensitive?