UPDATE: went today to the immigration office (still almost no one at j counter went very smoothly) showed them my passport and asked if it was a mistake, they were very apologetic and corrected it to a 30 day extension, asked me if I wanted to do the 60 day COVID extension right away as well but told them I would come back when my 30 days expire. They already gave me all of the forms for the COVID extension for when I’ll come back

I will go again to immigration next week to ask for clarification on my stamp and will update if this can be interesting for anyone else. I'm planning on staying beyond the 10th of october so want to make sure this will not be a problem (baffling to me that I might have to pay a fine for a mistake that they made ...)

Thank you so much for the clarification!