Maximum number of devices connected?

I continue to have issues with the internet dropping off randomly. It seems to happen only at night when everyone in the family is online. I have the 3 set Orbi RBR40. The weblink below states the Orbi can handle up to 250 clients, but for those who steam a lot of HD video and gaming (Which I do), no more than 50 clients. I am well below 50 clients and still have continuous drops every single night....  it is getting to the point of extreme frustration. 

https://kb.netgear.com/31097/How-many-devices-can-my-Orbi-system-support    

Currently connected:

4 cellphones

1 Nvidia Shield

1 Amazon firestick

4 PCs

1 PS4

(Not all of these are being used at the same time either)

-That's a total of 11 clients which is well below the "stated" limit for HD streaming. Also, I have Comcast internet of 150mbs, which should be plenty fast to support my needs. 

-The satellites are within 25ft of the main router with 1-2 walls max. 

I would really love to know how to fix this constant signal drop every night. I have to literally do a hard reset on the satellites. In today's day in age, with many, many people moving from cable TV to streaming, you would think these devices (which cost 400$+) would be able to handle the load.