White spots

[Denisecf]

Hello! I recently noticed this white dots in one of my philodendrons and I’m a bit concerned. What do you think it is? Do you ever had this issue with your plants?
I also notice this same spots in a new leaf of my fern.

 

[Marck]

This is unusual damage. it might be due to a fungal or bacterial pathogen but this is not clear. It is concerning that the same (or similar) damage is appearing on two unrelated plants: Heart-leaved philodendron (Philodendron hederaceum, or similar) and Bird-nest Fern (Asplenium australasicum, A. nidus, or a similar spp.).
Give the plant bright light and do what you can to reduce irrigation and improve drainage. Continue to monitor this situation. As a precaution, you may want to remove and dispose of any blighted leaves.