Thanks for fixing it! I'm a long time user (and contributor) too, but the change in the release process has been around for a while now (~2009).

You're right, I'm still not used to KDE Applications / KFlibs versioning... been using them since 1998, maybe too long?

Just a note: KBlocks is not related to Plasma at all. The sound works from the version of KBlocks part of KDE Applications 19.08, which means KBlocks>=19.08.