@Alexandre. 

how can I do this ?.... try connecting Eufy camera to ISP Router SSID.

Do you mean to connect the Eufy camera to the Wifi of the internet service I have ? (router of the internet company)

I did the connection like this....

All Deco units and Router(internet service) are connected to the TP Link Switch, only 2 decos are Wif Connected to the principal Deco unit.

But before that I did Step 1, the configuration in the Decos APP

I have my computers, cellphones and Smart TVs connected to the Wifi and all are well, running fast in the internet, Could I have this if I did wrong the configuration of the Decos to put it as AP mode ?

  @mariocaz 

Open Deco app. There is large "WiFi Settings" button in the top right of Main page. 

Click on that button, new screen will appear. There, you will see: Network name (SSID).

Find same information in ISP Router. You must configure different Network name (SSID) in ISP Router than you have in Deco app for Deco mesh. 

  @Alexandre. 

Oh ok, the SSID is the name of the Wifi that I put, of course the name of both Wifi are different, example.....

Wifi Name of the Decos:  Calakmul´s Home

Wifi Name of the Internet Router Service:  Wifirifi Lentium

And I have a 2.4 connection:  Wifirifi Lentium_2.4

So this is not the problem, what do you think in try with the TP Link Extender fot the Eufy Camera ?

  @mariocaz 

I am not sure range extender will help, you should not need it when you have ISP Router with its WiFi and Deco mesh with its WiFi.

Two recommendations:

1. Simplify Network Names.

For example, change what you have to:

CalakmulsHome

and

WifirifiLentium

No spaces between words, no other special symbols. Not every device likes them in Network Name (SSID). 

2. Then, as I suggested, find time when you can power off all Deco units. At this point you will only have ISP Router WiFi network. Try connecting camera to ISP Router WiFi. If you can't - this is not Deco problem. If you can and camera works fine - power on Deco and see what happens next.

  @Alexandre. 

Yes I didn't know that but now Is crazy change the names of the Wifi because I have more than 80 ítems connected to my Wifi networks, If I do that everything will be disconnected immediately and then I will need to connect again every appliance to the new Wifi network uufff hahaha

Do you recommend me to do that ? Hehe

I didn´t notice but also my AC Splits are disconnected and I can´t connect it to the Wifi of my Decos I think this happened when I did the Change in the Decos to put it as APqw or maybe when I enabled the Fast Roaming Option, I don´t know (I already disabled it), aarrggg.

The problem I see is I have more than 80 items connected in the Wifi, so any change I did in the configuraton something goes wrong.  =(

****UPDATE****

I just disabled the Beamforming option of the Decos APP and this fix the problem of the AC Splits Wifi Controls, it was complicated to know this was the problem because is an option that is enabled in the beggining when I did the switch of my Decos to AP mode, wow I was crazy with this too, but happy I could fix it.

  @mariocaz 

Yes, 80 devices is a lot.

You should have small number of devices connected to ISP Router now. You can simplify ISP Router SSID only and then follow steps I outlined earlier: connect camera to ISP Router WiFi, if not working - power off Deco mesh and try again. 

  @Alexandre. 

****UPDATE****

I just disabled the Beamforming option of the Decos APP and this fix the problem of the AC Splits Wifi Controls, difficult to know this was the problem because is an option that is enabled in the beggining when I did the switch of my Decos to AP mode, wow I was crazy with this too, but happy I could fix it.

Now the speed of the Wifi is a little slow in some places that was faster with this option enabled, but well no problem for this.

  @Alexandre. 

Bro, again thanks so much for all your patience with me and your nice help in my case.

Well I saw the "main" problem that some of my items/appliances disconneted from Wifi, others works in strange form (don´t respond with Alexa, intermitent connect/disconnect from Wifi, can´t control them well, etc. hehehe), like my Eufy Cameras, Ac Splits controls, etc. well I was crazy for these problems I have, a lot of items I have Wifi Connected, so a lot of problems to me, ok well the main problem was that the Beamforming option was Enabled in the Deco´s App, I disabled it and all seems to work fine again (Really hope so!)

But many thanks because I see that my mes is a lot better in AP mode.  =)

I want to ask you..... I have a Satellite Deco that is connected by Wifi but with very low signal, I want to connect it by Ethernet with a TP Link Power Line, my question is that I need to connect as the "sender" the Principal Deco ?? (because my X55 only have for 2 connections and are bussy) or can I connect the nearest Deco as the sender to the TP Link Power Line and then connect as the receiver the Deco unit that is connected right now by Wifi ?

  @mariocaz 

You can use TP-Link powerline adapters to establish wired link to Satellite Deco. I have good news for you: no need to connect second powerline adapter to Main Deco. In fact, with Deco mesh running in Access Point mode, second powerline adapter does not have to be connected to Deco at all. You can connect it to Ethernet switch you have, or even to ISP Router.

To help understand how powerline adapters can work for you: think of them as of very long Ethernet cable. You plug one end of Ethernet cable to Satellite Deco, another end goes to any available Ethernet port in your LAN.

  @Alexandre. 

Ok I did the order of the TP Link Powerlines, hope to receive them next week.

Only to confirm... Can I connect the 2nd Powerline device to any of the Decos I have connected by ethernet, right ?