What are your other parameters? Alk, Calcium, Salinity, phosphates and nitrate?
I have a similar FS. Mine Went from big and fluffy to exactly what you show. I had bottomed out my nutrients and my Alk was very low. I’ve since increased All my levels and finally after almost a month the FS is starting to extend again.
I also had/have a little bit of Dino’s. Looks like I’m finally getting ahead of that which may be improving the FS appearance as well.