Mi 11 ultra network bandwidth limit / low Download speeds

[lvaka]

Hello Xiaomi community, I am using my Mi 11 ultra(chinese - yet to flash EU rom) on Tmobile in US. I have a oneplus 8T as well which is connected to the same network. When I test these two mobiles, which are connected to HSPA+ right next to each other, I get 40mbps download speeds on oneplus 8t but only 10mbps on mi 11 ultra. Is mi 11 ultra or MiUi limiting the network bandwidth? Are there any settings that I can adjust to see the same speeds? Appreciate any help with this.

 

[xNAPx]

China phone has got bandwidth limitation in USA due to different bands supported at hardware level,no firmware can change that I'm afraid

 

[lvaka]

China phone has got bandwidth limitation in USA due to different bands supported at hardware level,no firmware can change that I'm afraid

These two phones am talking about, both support Band 2 which is where they are connected currently with varying download speeds. I can understand about band 66 which is not supported on mi 11 ultra.

 

[xNAPx]

if that matter I've seen different behaviours using different rooms in my flat in the same position checked everyday different times a day,

custom xiaomi eu.9miui 12.5.7) : max 300mbps
official EEA firmware (miui 12.5.3): max 450Mbps
official stock global firmware for my device (MIUI 12.0.2.0): max 550Mbps

try to change rom it may make a difference