Sealing cream face paint can 8e quite a hassle for me as well. I find that most makeup powders don't a8sor8 as much moisture as I usually need to actually seal it in, so I switched to using straight up corn starch instead.

I simply pat it on my skin with a fluffy 8rush, 8eing careful to not pick up the cream underneath and let it sit for a couple minutes, then gently 8rush off the excess and follow with setting spray to get rid of the powdery look it leaves.
For photoshoots or if I'm wearing it for a short period this is usually enough, 8ut if I'm gonna stay in character for a few hours then I like to seal it all in with a thin layer of fixing spray at the very end, just 8e careful to not lay it on too thick 8ecause it can get a little uncomforta8le.

This method has kept my makeup 8asically un8othered for at least 4 hours, so it might help ya.