SSL is working so you just need to get the htaccess right. It's hard to tell what will work as you haven't shared any code with us so something further down the rules might override these examples.
It can be different for different hosts so you need to experiment. I have several for differing hosts. Some hosts also won't update htaccess unless you unlock the file in the control panel. Others have a time delay.
You can test in this excellent tool: https://htaccess.madewithlove.be