I should be getting atleast 100mbps right? how can i achieve that?

i'm currently using a 3-pack Deco E4 mesh system in the following setup:

1. 1Gbps ISP router → Deco mesh (connected via LAN port on the 1st floor)
2. Deco mesh (wireless on the 2nd floor)
3. Deco mesh (wireless on the 3rd floor)

However, when connecting to any of the Deco mesh units via Wi-Fi, im only achieving maximum speeds of 45-50 Mbps on speedtest.net and fast.com. Based on the product information, I believe I should be receiving at least 100 Mbps. Could you please clarify why I am only experiencing half of the expected speed?

I am using the default configuration in the phone app, with both 2.4GHz and 5GHz bands active, and QoS is turned off.

I would appreciate any insights or advice on how to improve my network performance.

thanks