Read the forum guidelines
I have had 2 Cox Techs out here. They found no issues and see 1.1Gbs directly on the line. After the modem I only get ~300Mbs. I contacted Arris and they have stated that their specs for the SB8200 require an Upstream signal power range of 45DBmV to 51 DBmV. I am getting roughly 35DBmV. I spoke to a Tier 2 tech on the Gigablast team who stated they cannot increase said signal power. From my own research online it seems like this isn't true. I posted in my signal readings below, any help would be greatly appreciated.
Current System Time: Thu Jan 10 13:20:45 2019
Only Cox can provide the acceptable range of signal strengths for your particular plan and device...not Arris, not Google.
Generally ranging, upstream power should be between +37 to +55 dBmV but ideally closer to the middle at +46 dBmV. Yours appear to be in the low end but, as I stated, it really depends on your plan and device.
Will the low signal cause my download speed to be 300Mbs or less?