Arris G36 slow upload speeds

I signed up for 1gig service in a mid-split upgraded area. I should be getting 100mpbs+ upload but I only ever get 40mbps, consistently. Upstream OFDMA seems locked and operational and has an acceptable power level (Upstream OFDMA at 47 dBmV). I have no splitters in my house. I don't understand why I'm not getting higher upload speeds. I've talked with support and they've reprovisioned and rebooted my modem but the upload speeds are still slow.

If the modem is directly connected to the rg6 coming in my house, and the signal seems acceptable what else could be the problem?

I can get 855 mbps download on wired ethernet, but the upload speeds are always capped at 40 mbps.

Is there a filter or something that has to be changed outside of my house?

Thanks.