Help! Don’t know what’s wrong with flame angel!

[Deinonych]

Okay so let’s say it wasn’t the same because I’m honestly not sure. What could I do about this? If anything?

Without a QT, there's very little you can do at this point. It's unlikely the fish will recover if the difference in salinity was too great. Fish can handle large drops in salinity, but their internal systems can't handle large increases.

 

[Tahoe61]

Was the water in the bag and the water in your tank the same salinity

+1

Many LFS keep salinity lower than optimal (typically ~SG 1.017) to save costs on salt. If this was the case and you only acclimated for temperature, the fish could be in osmotic shock.

^ yup.