All Plasma users who stuck to the default Solus Plasma theme will notice a change to their theme this sync. Old Solus Plasma theming had been partially broken for awhile and fixing it has made existing installs load the old theme. To switch to the intended theme switch away from Solus PlasmaDark/Light and back again.
Theme before switching away and back again:

Theme after:

Or just leave it if you like it how it is.