Cisco Routers :: Failing RV016 Or ISP?

I have a rv016 that's been in 24x7 operation since I bought it a few years back.  It is out of warranty.  It is connected to three cable modems on WANs 1-3.  Behind it are a bunch of PCs getting IPs via DHCP.  There is a gateway to gateway vpn tunnel setup on wan3 to a rv082 at another site.  There is a forwarding entry for http to an internal http server.  Everything else is pretty much default.
 
The router is primarily used to aggregate bandwidth for uploading large numbers of photos.  The systems behind the router initiate the uploads and the router automatically load balances the outgoing bandwidth.
 
This was all working fine until just recently.  The ISP is Knology who is upgrading each of the 8m/768k cable modems to 25m/5m.  They are also moving from DOCSIS 1 to DOCSIS 3.  They are currently in the middle of this upgrade and have upgraded the modems to DOCSIS 3 as well as the speeds to 12m/2m.  The problem is that the rv016 Network Service Detection, which is set to "Default Gateway" indicates that the modems fail randomly.  Usually only one will be failed, but up to two will fail the Network Service Detection simultaneously.
 
Knology insists that there is nothing wrong with their modems.  I have removed a modem from the rv016 when Network Service Detection indicates it is in a failed state and connected it directly to a computer.  It will work, but it has a different IP address and default gateway.  As soon as I connect it back to the rv016, it works there too, but on the original IP address and gateway.  I've only tried this test this twice so far, so it is a bit inconclusive.
 
Speed tests behind the rv016 are the same as directly connected to one of the cable modems.  The router works normally as it has for years.  Nothing else is acting funny.
 
So my question is, is the rv016 failing or is the ISP having problems?