Cap on devices router can support?

I have installed several "smart" switches throughout my facility. During the course of installation other devices have become disconnected from the router. Seems almost as if there is a maximum number of devices that could be connected at any given time. Most of these devices require the 2.4 network, I shift everything possible to the 5 ghz. This percieved limitation seems very odd considering the rise of smart devices. A quick google search shows most routers able to handle between 100-250 connections, obviously that isnt feasible. Ive read linksys routers are defaulted to 50 and that is adjustable by the administrator. The comcast business ive spoken with, including tier 2 support have no idea what to do with this issue. Im looking at a maximum of 40 to 50 devices, the majority of which are light bulds or wall switches. It seems foolish I would need to buy another router to accomplosh my smart set up when im forced to rent\lease one already. Any advice is welcome.

My Comcast router is technicolor brand, model dpc3941b