I had this problem with my angelfish. I had two angelfish and a gourami in a 36 gallon. The male angel and gourami bullied my female angel, nipped her fins down and wouldn’t let her out of the corner of the tank. I got tall plants to try and break the line of site, I rearranged the tank, and even tried making a wall with the plants and none of it worked. They never let her out of the corner of the tank and I worried her fin damage would get worse or infected if I left it unattended.
I moved her into a community 20 long with a different male gourami. She’s loving her best life in that tank. I did a ton of research on how to help her with the aggression from the other two, and ultimately after trying the other couple ideas, the only thing I could do was move her.
