We fixed the second critical issue on your end.
Please check again on your end.
And the first mixed content issue is caused by your imported images.
For example, your logo image.
Your logo image URL is not secure like screenshot.
But your website is https secure website, so you are getting mixed content warning.
It is not related with our theme. It's just image URL issue. You can replace your image on your current https website.
Then, you can solve the first warning issues.
If you have any other questions, please let us know again without hesitation.
Best Regards, C-Themes