What is the most stable firmware for R510 and ICX7150? My R510 randomly reboots which is annoying!

[dariusz_basiaga]

I have Lennar "Smart Home" which comes with 3 R510 AP's and an ICX7150 switch.  I have updated the R510 to the latest firmware since my past firmware would cause a random disconnect for wifi devices.  For example I would be watching a movie on my phone and then suddenly I would see the WiFi signal just disconnect and wifi connection just dissapear.  The phone would switch over to Cell data for about 10 seconds and after about 10 seconds the device would regain wifi connection.  Now mind you, that I have not moved from the spot I was either sitting or standing.  The stream was going perfectly fine for X amount of minutes prior and the signal strength was full.  So no real reason why would the signal suddenly drop.

Now for streaming that is annoying at most, but when using a cell phone via wifi calling this causes dropped calls.   I am in a bad cell phone coverage area so I am forced to employ the wifi calling feature and it works ok when it works and horrid when it doesn't.  

So which firmware version is the most stable and why the hell does the system keep randomly dropping devices?

thanks!