@richard.benard 

Hi, may I know the model no. of your Huawei modem? We will need to check the LTE category it supports.

Besides, please check the network type and band on Advanced->Status page of the MR600, then check if the Huawei modem uses the same band(s) or not, if not, please try to change 4G band manually on the MR600 to be the same as that of Huawei modem to see if the speed will be better.

Here is the instruction about how to select 4G band manually on MR600:

https://www.tp-link.com/en/support/faq/3099/