poor text quality on export

Hello everybody,

I've seen a bunch of forums regarding poor export quality on premiere pro, but still can't solve my problem.

I edit videos occasionally, but I've never come across a problem like this in my previous edits.

When I export my video (1080X1920 phone format) the parts of the video where I inserted text or JPEG pictures sound very blurry, the video parts are intact but all the places where I placed text (coming from premiere pro) loses in quality when exported.

I've tried changing the text, the font, starting a new project, the quality (I've tried exporting in 4K), going for a walk through the sequence settings, but I can't find the source of this problem. here are screens of my settings, of the final rendering, if that can help you (i'm sorry, it's writing in french). 

Thanks a lot !