Download speed not changed after switch from 25/25 to 50/50 service

Hi, I recently upgraded our service from 25/25Mbps to 50/50Mbps.  After the change I noticed that speed tests were not showing the promised speed levels, and I had a chat session with an online agent that led to them trying to get me to upgrade to Quantum service hardware.  I have a Verizion Advanced Wi-Fi router that has been working fine.  I monitor my connection in the FCC's SamKnows program, which monitors my connection statistics.  It shows that after the upgrade, my upload speed doubled as expected (from ~30Mbps to ~64Mbps), but my download speed has not (still averaging around 30Mbps).  (Screenshot attached) . How can I convince Verizon to actually look into and fix this?