How Do I Setup 'Let's Encrypt' To Work With My WPMS Subdirectories Install?

Hello,

- I have a WPMS install using subdirectories.
- I am using Siteground as my host provider, which they offer 'Let's Encrypt' setup.
- I've already enabled that on my domain and it works fine... only when you go to the primary domain. It doesn't seem to be working when you attempt to visit of the sites i create within my WPMS install. However,...
- When I attempt to login to one of the other sites (from its respective wp-admin login page), I enter my login and password and hit the 'Log In' button. Instead of logging me in, it simply reloads the same page and clears my fields.
- When I click on 'Lost your password', I get this error message:

This site can’t provide a secure connection

http://www.my.feedbackscout.com sent an invalid response.

Try running Windows Network Diagnostics.

ERR_SSL_PROTOCOL_ERROR

After researching the ability to use 'Let's Encrypt' with WPMS, I believe their website states that it doesn't support WPMS (yet) when using subdomains. However, if using subdirectories, it should work fine. Ultimately, this is what I'm attempting to do.

If I can get assistance in this, I'd greatly appreciate it. Thanks in advance.

Regards,
- Sammy