I got a 25EUR gel nail polish curer, with 12W of 405nm LEDs. I tested it with a drop of resin on a matchstick and it cured it in about 1 second. maybe you can do the same test with yours?
Generally the wavelength isn’t that specific, so I’d be surprised if 25nm made any difference.
If you are trying to remove the sticky surface feel, then washing with warm water is better in my experience. The stickiness left after the IPA washes isn’t all curable, some is just a residue of what didn’t dissolve in IPA, but it does dissolve in water.
Andrew