The wings disappear when you disconnect from the world or server, but the effect remains so you can still fly but you look like Superman and that's not cool.

did u find a fix or alternative way?

did u find a fix or alternative way?

Nope, I decided to remove the mod until anyone get me some solution.

Having same issue with a Server, hopefully there's a fix soon

I fix it myself using command blocks (not very good but it works)