Arris G36 Only Getting 42Mbps Upload Speed for Superfast Plan

Hi, 

I have an Xfinity Superfast Plan. The speed mentioned in my plan is

Upload speeds: up to 150 Mbps

This is a screenshot from my Xfinity homepage after logging in (Notice it doesn't mention my modem as Arris G36):

I have an Arris G36 modem. I checked on Xfinity site and saw it is an Xfinity NextGen Speed Tier Modem model as of Sep 2024. Please see https://assets.xfinity.com/assets/dotcom/projects/cix-4997_compatible-devices/2024.09.18%20Full%20List%20of%20Compatible%20Devices.pdf

Below is a screenshot of the doc

This doc is directly linked from the Xfinity website after I logged in under "All Compatible Devices".

I visited an Xfinity store and the customer representative verified that my address is compatible with the Next Gen Tier.

Given I see that the Arris G36 is one of the Xfinity Next Gen Tier modem, I expect to see upload speed for at least 100Mbps. I'm seeing upload speed max at 42Mbps. I tested the speed by directly connecting my laptops and PC to the Arris G36 via an ethernet cable. I have restarted the modem many times hoping I can get a new firmware update.

How can I get this faster upload speed? I already called Tech Support but it didn't really help. Do I need a technician to come to my house in this case? 

Can someone at Xfinity take a look at this issue?