But newest stable ISO based on 5.13: Manjaro - KDE Plasma and link to download is https://download.manjaro.org/kde/21.1.6/manjaro-kde-21.1.6-211017-linux513.iso
Not many users visit the Update announcement threads ([Stable Update] 2021-11-19 - Kernels, Gnome 41.1, Plasma 5.23.3, Frameworks 5.88, LxQt 1.0, Xorg-Server 21.1, Mesa) as they need not an update but full release - image file. Furthermore 21.2pre1 with 5.15 was on manjaro.org earlier, but not now already.