I have two fedora 43 kde-plasma installation a pc and a laptop. On my pc I have a version 33.0.0 which probably wasn´t installed from the fedora package manager as it has the 3.17 version only and is run in a bwrap.
At the moment, version 33 is the main version-number of nextcloud. The nextcloud-client is actual 4.0.6. And yes, Nextcloud should handle the version-numbers in a better way (nextcloud 33 is called hub winter 26, and the clients on the download-site are called 33, but is version 4 …)
After version 4.0.8, they switched to semantic versioning and aligned the major version number with the latest server release: 4.0.8 → 33.0.0 → 33.0.1 → 33.0.2 (latest).
So, the Fedora packages are several versions behind the latest Nextcloud release; that’s why they are still on 4.0.x.