My friends electric blue cichlids mouth is all white and puffy.
I just did a water change. And none of the other elec blues are like that. Nore are my ob peacocks. I hear it's just them with the pecking order
The photo isn't the best but it could be mouth rot. Just to let you know, that appears to be a blue zebra whereas electric blue cichlids often refers to the blue ahli.
African cichlids will often lip lock to establish dominance but this might not be the case. Most the time you will see dark "bruised" lips, not white and torn up lips. That fish is too young IMO to even begin lip locking as it is most often adult males going at it and sometimes females. Is the fish eating? Can you tell us the parameters (ammonia, nitrite, nitrates, temp) along with tank size?
I see many things wrong here. 70 is a bit cold, 75 is ideal. There should be no ammonia or nitrites in the water, both are harmful at even small amounts. This could be the main cause of his mouth issues. Water changes need to be preformed to get the levels down. Sounds to me the tank was not cycled (Nitrogen Cycle) before adding the fish.
20gals is far too small for African cichlids. Blue zebras get tight around 5-6 inches, same for peacocks. A 55 gallon is the smallest tank I’d keep them in.