The question is... is it fuzzy algae which is like black beard algae or is it flat not fuzzy, brown, and wipes off easily which would be diatoms. Diatoms are common in new tanks where there is excess silicates. They are unsightly but will go away in time. You can easily keep them wiped off an anubia but they will come right back. Nerite snails, oto's, and bristlenose plecos all help by eating diatoms. If it's BBA then there is only a couple types of fish that help control it but it's better to improve circulation around the plant, move it to a shaded position, and if needed treat it with Excel. In the picture of the other anubia, it appears to have yellowing leaves which indicates a nutrient deficiency. Are you dosing any ferts?