All organisms have an "optimum temp" in which that organism has evolved in to survive, be they bacteria, or fish, or birds.
Go only a few degrees below, the organism starts to become stressed, same if temp rises above.
N haitensis evolved in temps in the high 80s, and should be kept in those temps.
All Gymnogeophagus come from temperate and/or subtropical waters and need a cool down for a proper life cycle. Eliminate that cool down, and the stress creates disease potential, aggression, a shortened life span, and/or sub par appearance.
I believe all fish should be kept at their optimum temp for best color, growth, and health, and a little research may give the best results.
I keep Alcolapia in the high 80s 90sF,
Uruguayan cichlids get a cool down at least down into the low 60sF
just as I give northern Mexican species such as H carpintus or beani into the low 70s to mid 60s.
Temps in the mid to high 80s is also optimum for the bacteria Flexibactor columnaris (cause of duck lips)
unless the fish has evolved to resist it.
Just as a sudden drop in temp can bring on ich.