added a new convict now problem

[Krisk]

I have a 55 gallon . 1 peaceful electric Blue Acara and 1 geo heckleii also know as threadfin Acara the two been together for 6 months they are both a good 3 inches. Today I added a 2 inch blue convict it’s acting super bully hiding and dashing out into both fish . Trying to back them up in corners. Do I keep or return this fish . What else can I put with a EBA the geo heckleii. Any advice will help . Also should I give it a few days or fast return ?