@AshTheDash For 8 ports, TP-Link recommends the following switch: https://www.tp-link.com/en/home-networking/soho-switch/tl-sg108/ In general, look for TP-Link brand of gigabit unmanaged switch, 5-...

@DavidWalsh DavidWalsh wrote @DavidWalsh Just a quick question, can the 1.6.2 units have their firmware reverted to 1.1.2? You can't use firmware from different hardware version. This is how to find...

@DavidWalsh As I suspected. For the same Deco model, such as M4, TP-Link produces it with different hardware versions. Then, it provides firmware with different feature sets for different hardware...

@Alfkbort See the following recommendation from TP-Link: https://community.tp-link.com/en/home/forum/topic/669676?replyId=1365154

@DavidWalsh I think I have an idea why you do not see Connection Preference option for this installation, but I need more information from you to be sure. For that new setup, open its Update Deco...

@AshTheDash "Can the Deco M9 Satellite deco units connect with each other even if they don't have line of sight?" Yes, they can, but it is not guaranteed. You have to try it at your place, because...