Yeah that happens in my Vieja bifasciata 210G tank.. I should try feeding the plecos in that tank when lights go out, but I never do.. I feed 1 time daily 4-5 days a week. Pellets / flakes and a few wafers in the front of the tank for the cichlids and tetras and more wafers in the back where the more reclusive plecos typically hide.. In my SA Cichlid tanks the cichlids and tetras usually attack the food up front, while the more reclusive plecos can feed on the wafers in the back.. But I have no idea how plecos eat in my vieja tanks..

I actually just replaced a slow growing L25 from my Vieja bifasciata tank w/ a fast growing L600 from my G. sveni tank hoping the L25 will be able to eat / grow more away from the greedy viejas..
Fortunately my L95s are in SA tanks and they're growing faster than any other pleco in my fishroom...
What fish are "the other greedy fish"? Looks like an Oscar in the background. Maybe you can try feeding when lights go out at night...?