Hi and welcome to the forum
As fish keepers we aim to provide the best care. Members on the forum base their advice around what works well, based on the needs of the specific fish.
Advice is provided based on experience, science, and proven facts.
The best thing you can do is provide separate tanks for any incompatible species. As stressful as this can be, it’s about the fishes welfare at the end of the day.
Following advice could help prevent you further problems down the line.
I hope this help, best of luck.