Ive had sps bleach out and make a comeback on the back of 1 little polyp. Ive sps where one polyp died from a sting or fall and the next day the entire colony was bleached beyond saving. It's alot of luck. Some make it. some dont. All you can do is repeat the same thing over and over and expect different results. Kind of sounds crazy but we are trying to keep small portions of a thriving underwater reef in a small box insinde our homes, which is also kind of crazy.
Keep algae from growing on it. Keep fish from pecking at the dying parts. Keep water parameters stable. Cross your fingers. Observe it as much as possible to determine if light and flow are an issue and move if needed. If it was healthy to start you have better chances. If it wasnt growing much to begin with and never really thrived then it might be the end. Hardier speceies/specimens can survive alot. I had a purple stylo recover from a near bleach out after falling under some rocks. Ive had newer acropora frags literally bleach in under 10 minutes for no apparent reason.
Good luck.