@Helga I recently bought the Deco M9+ model for my home. I love it but had issues setting up my IP camera to the WiFi network (there is NO way of manually adding IP address of devices/manually configure in the app--it's not a supported feature). After a live chat session with a TP-Link agent, I was informed that the IP address of my IP camera was NOT within range of that of the router which was 192.168.68... My IP camera was 192.168.1... Therefore, I had to change the LAN IP of the router in the deco app. After doing this, it was able to automatically detect all devices with an IP address above 192.168.1... This change allowed my IP camera (Hikvision) to be connected to my WiFi network. To remotely access the camera footage, I used Port Forwarding in the deco app and inputted the appropriate information (port numbers, etc.). Now everything is working well and I am happy I didn't have to get a new mesh WiFi router because the M9+ is really good thus far.

@DIYer20 

Your camera would have been issued a new IP address by the Deco router if you had reinstalled it as is typically required for all  IP cameras when changing routers.  There are many devices that require reinstallation after installing a new router (cameras, lights, vacuums, thermostats, etc.). 

This is because every router typically acts as its own name server and handles the IP addressing leasing process for the devices conntected to it.

@LeonardodaVenci 

Even if my camera uses a static IP address?

@DIYer20 

Typically no IP camera has a static address.   Usually the camera's address comes from the DHCP protocal that was in force when you install the camera on your WIFI network.  For most wireless IP cameras this is accomplished by using one of several methods depending on the manufacturer.  The most common way is to connect the camera to the network using a wired connection, and then providing wireless information (SSID and password), and restarting the camera wirelessly.  Some cameras let you pair a phone a to access a camera installation network and then providing the wireless information.  I believe you said you had an HIKVision camera which has DHCP unchecked by default, and uses a propiratary software solution SADP.  They are the only camera company I am aware of that does this.  SADP allows communication via a subnet with a 'rogue' IP address, so long as the subnet on the computer running SADP is the same as the camera.  This is a very unusal method and does not conform to any networking standard.  In the camera setup you can actually check 'Enable DHCP' and your camera will get it's IP address from the router like every other network device does. You can also check to enable P2P and setup your camera using a mobile app.

My foscam also did not want to connect, only after switching off fast roaming it worked. Both TP-link and Foscam are pointing at each other to be causing the problem..

@LDE 

Many older devices do not support the 802.11r standard otherwise known as fast roaming.   I have discovered that many also do not support MU-MIMO or Implicit Beamforming. 

I really had trouble keeping my Foscam G2 outdoor cameras connected...to the point they are in my attic right now.  My Foscam R2C indoor camera is amazing and never loses connection.  The strange part...they use the exact same firmware.  I could only deduct that they have differences in internal hardware.

Here is the list of devices I had trouble with while using these three technologies:

• Some brands of wifi smart plugs (brands Dailymotion and Omotion)
• Roomba vacuums
• Neato Vacuums
• Sensi thermostats
• Remo S+ doorbells
• Swann Model SWWHD-OUTCAM camera
• SV3C Model SV-B01W-960P-HX camera
• Reolink Argus 2-Argus Pro-Argus Eco and E1 cameras
• Wyze Cam 1080p
• Foscam G2, FI9900P, and FI9821P cameras

When I disabled these 3 technologies, I could get fairly stable connections.  I hope this helps.

To be completely transparent I no longer own a Deco system.  I tried and returned the Deco M5, M9 Plus, and P9 systems.  I am currently using and am EXTREMELY happy with the Orbi RBR43 system i bought renewed on Amazon (with 3 year extended warranty) for $264 ($230 for RBR43 and $34 for 3yr warranty).

@LeonardodaVenci and @tplink 

What's so strange is that my first Foscam camera (4 years old) has no issues with fast roaming, but my new Foscam camera G4P (1 week old) can not handle it and only works with Fast Roaming turned off.. Still thinking of just keeping the fast Roaming feature off as it does not do that much to increased speed on the network..

@Helga

Same problem here. No troubles with R4M indoor camera, but both outdoor G4P camera's continuously loose connection. All camera's have same firmware and there is a DECO M9 Access Point in line of sight with both camera's with only some glass and piece of wood in between. So to say connection between R4M and nearest AP is far worse.

@Brambix I believe this is a Foscam issue that affects both the G2 and G4 cameras. I also believe it is a hardware issue as the software has proven reliability in other cameras. 
 

just so you know, I had connectivity issues with the G2 on all models of routers I own, both mesh and stand alone (DLink Netgear Orbi TPLink Buffalo and Asus) and the protocol of the router did not matter (AC300 to AC6000).