[Hummingbird] GZip Compression issue

Hi there, my hosting provider assures me I have GZip compression enabled on the server (https://checkgzipcompression.com/?url=http%3A%2F%2Finthesoil.on.ca), but I'm getting an error from Hummingbird:

Gzip is not working properly:

- Your server may not have the "deflate" module enabled (mod_deflate for Apache, ngx_http_gzip_module for NGINX).
- Contact your host. If deflate is enabled, ask why all .htaccess or nginx.conf compression rules are not being applied.
If re-checking and restarting does not resolve, please check with your host or open a support ticket with us.

Can you help? I've re-checked it several times.

Joe