Intermittent Connectivity Issue - Austin, TX - Time Warner Internet

This question is about "Intermittent Connectivity Issue - Austin, TX", with Time Warner Cable internet and apps. Ausitin, Texas, 78749. Single family residence.

Service: Spectrum Internet Ultra ( 400Mb down, 20 up )

Hello, I've been having issues with my connection. For the past month or so my internet connection has been intermittently dropping for about 8 seconds every 2-3 hours or so. This has never occured prior and just recently started happening. When this happens, the lights on the modem stay on as if nothing untowards is the case and the router maintains a connection to devices but does not provide internet. The modem registers events every time this happens.

I have used EMCO Ping Monitor to ping both google and the router's default gateway simultaneously, my computer only ever fails to ping google when the problem occurs, so I know my computer is not losing connection to the router.

I have had two technicians come by; the first replaced the coaxial cable ( was and still am using rg6 ) to my modem and made sure the outside connections were ok; the second confirmed both the lines to my house and next door neighbor's houses were functioning properly. I do not think any splitters are affecting the connection.

I have tried using a different modem from the one TWC provided, and have registered it accordingly. I tried using a different router as well, but the same symptoms still present themselves. I also tried using different ethernet cables ( I'm using cat5e ).

Current Hardware:

Modem - ARRIS - SURFboard SB6183

Router - ASUS - RT-AC1900

Current modem status page and event logs etc. ( the modem is online according to twc ) :

Status/Signal page -
Event logs -
Product Information -
My internet speeds ( I get what was advertised ) :

Out of curiosity I have also looked at the Spectrum Analyzer page for the modem

( ) to see if anything changes from the norm when the problem arises.

Sure enough the chart goes from this ( normal? ) ( Spectrum Analyzer ), to what I have crudely illustrated here ( probably bad ) ( Imgur ) only when I lose connection.

I'm not entirely sure what can be done to remedy this but I'm fairly certain my modem and/or router is not to blame as neither show any real indication of being defective. Either way I am planning on replacing the current modem but am not certain that it will fix the problem as the issue may reside beyond my house or at a connection I am unaware of.

Any help is appreciated.

Intermittent Connectivity Issue - Austin, TX?