@David-TP 

Well, if the less than functional Deco app is to be be believed, then the XE75 Pro firmware version is 1.2.11 Build 20240724 Rel 38913. The M9 Plus firmware version is 1.2.11 Build 20190926 Rel 55727. 
 

No doubt, you will be aware, that the M9 Plus units have to be initially updated using an app from 2021 before they can be updated to later versions of the firmware. Tried that, no success. Not even with laptop, router, and M9 Plus units being connected by Ethernet cable and mere millimetres away from each other.

The smart home devices I referred to, are part of a Ring security system. For security reasons, I am not going to elaborate further. They are all working perfectly, as is the wifi via the XE75 Pro and 2 of the M9 Plus units.

Now for the fun bit of your response - encouraging a user to install beta software on a functioning wifi mesh network. A fully functioning network at that. And all because an app cannot see the fully functioning devices.

The catch is, that if the user cannot get things to work, it is the user's fault for using beta software, and TP-link accepts no responsibility for the user so doing. And why should it, after all, it is beta software, and the user should have understood the risks.

For reference, before I retired, I spent 45 years working in I.T. Building hardware at component level, testing hardware at component level. Likewise with software. I've forgotten more technologies than most people know.

With all due respect, I'm going nowhere near using beta software. I know, only too well what can go wrong.

I repeat the request from my first message. Is there a way of accessing the Deco units that does not involve using the Deco app?

  @retired_user 

Can't figure out a better way to update the thread I started, other than replying to my own original message.

Just to say that the Deco app has both surprised me, and surpassed itself.

Without any interference or help on my part - the app was not even running - foreground or backgound - on my iPhone, yet, on running it out of curiosity to see if anything had changed, I opened the app, and to my amazement, the app was working as it should. Something it has not done for weeks. Unbelievable! In those weeks, a selection of networking apps on various devices have shown the TP-link hardware to be running OK. Just not the the one app that should be working - the Deco app. Until now that is. So how long will it be before the Deco app goes AWOL again, without any assistance whatsoever from me? Post your guesses here, and I'll let you know when it does.