Slow speeds w/ Gigabit plan. Looking for any help or solutions, please.

Just upgraded to gigabit speed plan yesterday. Apologies for the wall of text but I want to ensure I explain the information I have.

 

I made sure to do my research beforehand and purchased an Arris SB8200 modem that is listed on their website as an approved gig speed modem. I verified that my router (Netgear R6700v2) can support this speed as well. I also replaced all my ethernet cables with Cat7 to assure the best speeds and that I'm not bottle-necking my devices. I've verified that my PC's network card (Intel(R) Pro/1000 PL Network Connection) can handle gig speeds as well.

Since the upgrade I've noticed speeds around 250mbps at best on my PC (tested hardwired with AND without the router to assure it wasn't a router issue) and 350mbps or so on my devices such as my phone and my gaming consoles which seems odd considering I'm supposed to be receiving at the VERY least around 750-950.

 

Also couldn't help but notice that the lights on my modem are all solid green which indicates it's in DOCSIS 3.0 mode, however the manual says the middle two lights (downstream/receive, upstream/send) are supposed to be solid blue to indicate a High-speed Internet connection with channels in DOCSIS 3.1 mode. Is there a reason I'm not receiving 3.1 mode w/ my gig speed plan?

link for reference: https://arris.secure.force.com/consumers/articles/General_FAQs/SB8200-LED-Light-Status/

 

Basically, I'm just confused as to why my speeds barely surpass that of even my old plan of 300mbps when all my hardware is capable of the gig speeds (940mbps-1000mbps) that I'm supposed to be getting. Is it possible that the coax cable requires replacement by a tech?

 

Getting in touch with techs right now is close to impossible and even less likely of one coming to check things out but I'll be attempting to contact them tomorrow and hope for the best solution but figured I'd ask here and see what avenues I may have missed. Thanks in advance for your responses!