@Joshvu72 You can revert back to any of the firmware.  Just go to the TP Link Firmware Download site.  You will find all the different versions of the firmware there.

Here are some suggestions you might want to try to isolate the issue:

1. Shut down one satellite to see if the problem persists.

2. Shut down the second satellite and power up the first satellite

3. Swap the positions of both satellites and repeat steps 1 and 2.

I found that swapping out the satellites  appears to have fixed nearly all of my connectivity issues so far.

I find that firmware 1.06 is more stable than 1.04 and1.05 is the worst in my environment. YMMV.

  @FM-305 Quick update - I keep testing as I don't like the fact that I have to have a switch between my router and the satellite deco's to utilize the wired backhaul feature. So, this morning I removed the switch and played with the NAT forwarding settings in particular the UPNP. I found that if the UPNP setting is 'on', the satellite deco's will not connect via a Cat6 or MoCA adapters. However, if the UPNP setting is 'off' all works as expected and without issues. 
 

Note, my kids have PS4 and PS5 and both working fine with the UPNP setting off.

ISP, Fiber Adtran - Main Deco (router) - satellite Deco (via cat/6 or MoCA 2.5 adapters).

  @Mango3000 

Well....turns out that the real issue is 2.4ghz channel width selection and the inability to move to 20mhz. TPlink doesn't allow it on these decos so the 3 x BE95 and 3 x BE11000 will be returned.  That's too bad. I spent over $2k on the set up and worked on it for a couple weeks.  The speeds were great and the app was pretty good but the 2.4ghz network is pretty much unusable which explains all the random disconnects, Ring device dropoffs and general instability.  5ghz and 6ghz was great but 2.4 which is all IoT, some of the Arc Sonos and Ring was junk. May try Asus or Netgear next if they have usable 2.4 at 20. 

I'm hating these Decos. Satellites will randomly show offline although their status lights are green. I can't connect my iPhone when any of the satellites show offline nor can other family members in the house. The connections are so unstable. 
 

I've tried several different set ups. First was main into a switch that the 2 satellites then connect to. Second I tried the satellites connected directing into the main and also the main into a switch for whole house Ethernet.

Both set ups show Ethernet backhaul working but as I've stated, the satellites randomly go offline and wifi connections break.

I've turned off uPnP, beamforming and QOS. Regardless of simplifying things bother brings stability to the system.

Anyone with suggestions?

  @Joshvu72 Try using only one satellite and see if that works.  Using Wi-Fi only i.e. not using ethernet, what is the distance between all the satellites? The DECO starts weakening at about 40-60 feet, depending on how manyu walls and windows are between devices.

Are you using Allow List Mode (Security/Wi-Fi Access Contro/Allow Access mode)? If you are enabling that, you need to change your Apple devices setup. Go to Wi-fi, select your network and tap on the (i) next to the network name.  Scroll down to Private Wi-Fi Address and deselect it. When enabled, the Apple device will use random MAC addresses to connect to the network. The changed MAC address will be refused by the DECO. This issue also happens with ASUS routers as well and they do not have a fix for it. I disabled this on the Apples if you are enabling this option, otherwise use Block List Mode.

Netgear devices seem to get around this but I have issues with Netgear's reliability.  I went through three Orbis in six years. The main unit always  fail after two years (I see this is a common issue with Netgear Orbis).

I read this:

the 2.4 band is restricted to channel width of 20mhz, the wired backhaul doesn't work, and as others have mentioned is stuck in a loop back effectively, the DFS channels are unusable, unless you trick the system by removing a satellite- then it will allow you to select 240mhz channel width for 5Ghz - this whole this is a mess as others have said.

I also read this for ethernet connections between DEC units:

1. Please set up the Deco units on the same network via Wi-Fi at first through the Deco app before you wire them together.

2. Place the satellite Deco in the ideal location for the best coverage and then wire Deco units together with Ethernet cables, the Ethernet backhaul will take effect automatically.

Read this for more on ethernet backhaul.

Also, before using QoS, test your network speed using the app and remember the values.  go to More/Advanced/QoS and edit the total bandwidth with your values. I found out that this is extremely important for a stable connection.

I find Beamforming is useless so I disabled it.

Hope this helps.