It takes a long time to open the document for the first time

I use nextcloud and connect to the collaboration server from nextcloud. When I want to open a document (odt, odp, ods …), everything works, but opening takes a long time (6-7 seconds).
This only happens when I open the first document. If I want to open other documents, it works quickly.

COOLWSD (git hash: bcbca64)

Nextcloud Hub 3 (25.0.2)