Hard to tell, because photos are a bit blurry, but look could be bacterial, or looks a bit like Lymphocystis a viral disease that "no" meds are effective against.
If so it is ubiquitous like the common cold and usually appears after or during some form of stress.
Recently shipped fish often get it.
Agression in a tank is another cause, as are high nitrates.
Lots of Water changes and high water quality can help.
I had some Vieja breidhori get it right after being shipped.
I kept nitrate at 5 ppm or less and it disappeared within a week