Africian cichlids have black spots on there mouths

OK so this might be long but i have looked at so many sites to try to find and answer to why my 2 africian cichlids have black spots on there mouths and under there belly’s i just need to know what it is? and what to buy?some sites say its scabs due to digging under or moving gravel and others say it could be there diet i feed them flake food and VERY rarely they will get TINY feeders but there hard to come by here so its RARE when they do. there tank ph is normal tank is clean.HELP PLEASE
they have a cave and they dig to get in so theyre barely out only to eat.
my cichlids are: 1 is blue with blackish stripes and 1 is yellow with black strips but this ones stripes are more pronounced then the other.im worried about them exspecially the yellow one he is never out and barely does he eat he has black spots but mainly has lost his yellow and looks rusty in color and seems to look smaller in size.
thanks for the help
sincerely,
JESS