Thank you. As long as this is the Sprint Sierra Wireless Tri-Fi, indicating that your Tri-Fi is connected to the Sprint LTE Network, I would recommend 2 things. First, can you change locations, such as outside or down the street? Slight variances in manufacturing from these two different manufacturers can create this scenario if you haven't tried multiple locations. The TriFi may have a larger LTE antenna for example. If it still won't connect outside or down the street, and the TriFi does, re-activate your phone. ##72786# is a code you can dial into newer Sprint phones that wipes only the Sprint activation information. You will need a special code for the EVO LTE. You can call Customer Care and ask for assistance with this type of reset, or private message me by clicking on my avatar; although I'm almost off for the evening but will be available tomorrow.
Last resort if the above trouble shooting steps are not resolving the problem, and you've ensured that CDMA + LTE is selected in your mobile networks settings, will be a hard reset.
Let us know how it goes,
Sprint Tech ~ Sprint.com Communities
Available ~ Friday, Saturday, Sunday