Rbre960 ( ORBI66 ) - dropping offline frequently.

My RBRE960 had been stable up until the last few months. I have the router and 2 satellites. 

Recently,  the Router has been dropping offline for about 2 min. more and more frequently over the last few months. I'm on the newest .15 firmware. ipv6 is turned off. i don't have armor. i reset the Router a few days ago for 2 reasons. 

1. Frequent dropping out. meaning, i lose internet, completely,  the white light flashes on the router and i wait about 2 minutes for it to come on line again. 

2. i had the same issue as a lot of people and lost my access to my router either online or thru the Orbi app.  (assuming this had to do with a firmware update)

a reset of my mesh system allowed me to gain access again but did not improve my Internet drops. 

sometimes i get a few days without noticing a drop, other times i will see multiple drops in the same day .

I'm wondering if my drops  might coincide with the IP lease from Comcast. i noticed the other night it dropped offline right about the time my lease was set to expire. ( my lease currently only appears to be obtained for a 2 hour period and i read about shorter lease times having higher overhead and therefore a potentially higher likelihood of the ISP struggling to renew my lease.) 

I'm trying to get a hold of Comcast tech support but not having great luck.

I'm wondering if any of you have come across this already. I'm 

I'm also wondering if the newer firmware is more temperamental for obtaining leases and if i should revert back to a prior firmware and if so, should i bypass .31 and go all the way back to .21 ?

any other thoughts are welcome.