Slow upload speeds after plan upgrade

Hi,

I recently upgraded to the 1 Gig plan with an Xfinity XB8 gateway on a Mid-Split upgraded street (Broadband Labels show ~293 Mbps upload available at my address). My XB8 is locked onto 4 ATDMA channels (47.0–47.3 dBmV) and OFDMA Channel 43 (41.2 dBmV), and I'm getting 770+ Mbps download, but my upload is still capped at 38 Mbps. Can a Tier 2 specialist check my account's provisioning code and push the Next-Gen Mid-Split boot file to my XB8 without altering my $50/mo 5-year promotional discount?

Thank you,

Paul