It seems you have redirection in place. Depending on the WebService you are using - Apache/Nginx this can be in a different place. We’ll review both situation
Firstly, you’ll need to learn how block learn in Nginx. There is a really good tutorial from DigitalOcean here -
Once you know where and what blocks are used for you can check the Let’s Encrypt installation with Nginx
It will show you how to secure it.
Now onto the problem itself. Check the Nginx configuration for your website/application and see if there are multiple redirections placed. If there are multiple ones, you’ll need to remove at least one.
Now, Apache doesn’t have blocks but there are vhosts. If you are unsure how to configure them, you can check how here, again a tutorial by DigitalOcean
Once you now how to configure Vhosts, you can see how to configure Let’s Encrypt by reviewing the following article :
Now, Apache can have two places where the problem may be experienced. The first one would be your vhost file, you can have some redirection rules there.
The second place is your website’s .htaccess file. Check if there are any redirection to https.
The last place you should look would be your website and see if there is any redirections set there.
Now, we won’t be able to help with the website however if you are unsure, you can post the configuration file of your WebService and we’ll try to help out.