as you can read here there is a problem with kernel 6.0 and broadcom-wl.
Manjaro normally starts the newest installed kernel. If you want to start manjaro with an other kernel you need to choose it via grub-menu.
Also normally grub-menu is hidden while start. You can tap ESC or hold SHIFT while boot to let show the grub-menu. Or you make it always visible like discribed in here: