XB8 Bridge Mode Upload Speed Bug

Hello, I recently upgraded to the 2 Gbps (Gigabit X2) plan and received an XB8 gateway. Whenever I switch the XB8 to Bridge Mode so I can use my own router, the gateway gets pushed an incorrect legacy boot file. My speeds instantly drop to 1.4 Gbps down and 40 Mbps up because it fails to lock onto the Next-Gen OFDMA upstream channels. Can an official agent please help me? I need Advanced Support / Tier 2 to manually push the correct mid-split Gigabit X2 boot file to my XB8 while it is in Bridge Mode so I can get my full 200+ Mbps upload speeds.