@cberni1 

Other users have reported the same issue with Nest cameras connected to any mesh network: https://support.google.com/googlenest/thread/11958016?hl=en

Some of the things users have tried are:

-Disable Fast Roaming

-Enable the guest network, only one band, and connect the camera to that

@Tony Just as an opposite datapoint I have 2 Nest IQ Outdoor Security Cams and they have worked flawlessly on my M5 "3 puck" system.  The only thing I do notice is that ONE of he cameras always connects to the M5 that is on the other side of my house rather that the M5 that is less than 3 feet from it.  If I power cycle that cam it will connect to the close one then eventually jumps back to the one on the other side of my house.  I have MESH turned off on the 2 camers (because they don't move) and are both set to PRIORITY with beamforming and fast roaming turned OFF.  I have tried other combnations of those switches but same thing happens.  They are constanly monitored and no drop has been seen.

@Tony I have a Deco M9 Plus and also experience the same thing with 2 cameras that continuously go offline due to wireless drops.  I have them on a 2.4 GZ guest network only and still no luck.  What gives...

@cberni1 I also have the Deco M5 3 piece system. I've only had it a few days and all 3 of my cameras are going offline randomly for 15min. It's driving me crazy. I've done everything everyone else has done and still having the issues as well. I'm frustrated. There is no logical reason for the cameras to drop. I didnt have this issue with my old Netgear router. I went with the mesh system to give the camera in my garage a stronger wifi singnal. Not sure where to go from here. I've already invested the money in this M5 system.

@ClaytonB After a long battle with troubleshooting, i ended up selling all my Nest cameras and moving to a PoE camera setup.  I did so because from what i could surmise, the problem wasn't necessarily with the Deco Mesh system but rather the 4 nest cameras i had running simulataneouly.  I am running ATT 75mgb internet but my upload speeds rarely get above 5-6 mgb.  The problem with that is Nest aware utilizes upload to capture and record live feed along with any events.  With upload speeds as slow as mine, i don't think my internet could handle that much and would eventually drop one camera out at a time for 15 minutes.   Eventually, i just got tired of the disconnects and sold all of my cameras.  I will say that while i can't prove this theory to be true, it would seem to be logical because I never had this issue with 1 or 2 cameras.  As i added more cameras, this problem persisted.  

All of that said, i don't know how many cameras you are running and if this would be your problem, but I will say that as i continued to troubleshoot, it looked more and more like a Nest issue because every other connected device in my house runs over the Deco without a problem.  Unfortunately,   I also can't rule out the Deco causing some of this either which makes all of this very hard to find root cause.  For those reasons, i just got rid of the cameras and went to something that didn't need a wifi signal.  I know that's not the answer you want but as i scoured through internet forums, i found more and more evidence that Nest and wifi cameras continuously have this issue.  Hope this helps.

@cberni1 Thanks for the info! I have 3 cameras. I added two more at the same time I installed the M5. I only have 10mbps upload speeds so I do think you are on to something. Again, thank you for the info!

I never had that problem with my M5's but I only have Nest IQ OUTDOOR models and just 2 of them. Not sure which models you all have. Do you have the newer IQ models?  I have since "upgraded" to M9s and don't have that problem with those either.  They still will not always connect with the closest M9 but often choose the one 60 feet away not 6 feet away. I have 350/20 internet if that matters. 

@RetiredInFl I have 3 Nest Cam Outdoor 1080p cameras. My cameras dont always connect with the closest M5 either. When it disconnects, It's always one camera at a time. Two of the cameras stay connected durrin that time. When they all work, they all work great. No issues. I just get alearts about 10 times aday saying a camrea has disconnected, usally around 15min when it happends.

@RetiredInFl I had to regular outdoor camera version.  I don't have the specs in front of me for upload speed usage per camera that NEst told me, but I'd imagine with the IQ cam and 20 meg upload speed, you're doing better thna I was and the other person here.  Again, i'm not directly saying thats the issue but it's a logical conclusion to the or one of the issues based on all the information and evidence i've found.

@ClaytonB This was almost exactly my experience.  One at a time and numerous times throughout the day.  Rarely the same one back to back which makes the idea of recorded events being uploaded and upload speeds a more plausible answer.