Hi again,
It seems it is possible but you must to test it.
I tried to download TextLCD via a link from bottom right
Download repository: zip
Then placed it to project’s folder and reload the Studio or reactive the project for sure.
If you want to create whole project, you need to download whole MbedOS from github, then create a file with name mbed-os.lib and inside place a correct commit ID also from the github in correct format https://github.com/ARMmbed/mbed-os/#9a8c9e2c297f64c805698d72cd541ff3cd7fe538.
Mbed-os (folder), mbed-os.lib and a empty main.cpp place to a new project folder and then start the studio.
However, the best would be more describe your issue with network connection, then the Mbed Studio team can recommend a solution for you.
BR, Jan