On retail with shadowlands...

Wow 9.0.2
WeakAuras 3.1.2
Frost Mage level 60

Describe the bug

The spell "Fleshcraft" does not seem to trigger when set up for "Aura Missing"

Do you have an error log of what happened?
There doesn't seem to be an error, but might not be hooked up (a new spell)

Here is the export...
!WA:2!DjvVUTTou4AKcua1GIgJ0G07uWDOaDjOXoXzmWYrg2T(hvk1KoyaxkXJSiUYKQKuoo3rJm0Xc)i45o5H(aKNabJ(au0Po7NGskBKHYbEo8NVZ578DoLAwECzszYxoAHIhobeskNDyPHZxRGPQmbCTaN2LtG09B0PExx)(2DQ34D1V8Y2(TVYzfotfZf9tvAysl0nuIk(UDft7hfjbvjuipHlEBRl(9HfRwx8ZVwS2X9XV54Zplymvi4IyXTBbSqaJ0HY)2uqSLblJe4XGNsGv4DMhKamIHqv0CyjMfQtVlNYubnC657GwszrCXySHqwlc5mcDd3e4WcNAiPcluwbrugvgBzRnkRzkbD0iD5)Sxj26(DBLMfiCMax5EZUmfssOe5)euTYP1QEYkDwcJbPxm)M(SvYctxQuszJqWeqZPwaorf)lzwqXzxberNI8CD60zwr4AtKwp8SxwK(5LdBu3ZFONFDKVDMMCbPj4BbbIPLbP16mj4mvxmEBW)PfeiqdSqYA50XT5h6mpJTTiSs3Zu3ta)nNnk33Eu(ttpVntbIiCimOoHO1Lbxd4)RUPmh4YVbefUDbcfpyZTM9tQTMAWXWjxTzw59P7rOYqbOGHcUQq3lnhZOBAb1Y3V59awA6FaBKk(j5V0MXzWkIoCMFm0OYcjyAvYzMVAQK8Q2JXuwZ8kAa5vZpn)S8AA7l(7B(xkzDpaih1mbKXHcCKAUesIkMjYFocNKgJ3rRrsSYKriE2d0mqNZi6iR1BgJAAMZmjpWRbYXP3cDFbvmokTcIb6Oy1D7guGg(KDchtQzRBIHhGgNLOOwOWeSuEqUJLTK()GXPsgLSCA0RD)87tpRhsuwIQE8jhxP8KF8X)m

Whether it is "hooked up" or not is decided by blizzard. You used the wrong spellID (324867 is the correct one)

I suggest an addon that helps you figuring out the spellID by mouseovering the buff if you're having trouble to find the correct ID.
Like: https://www.curseforge.com/wow/addons/idtip

Also check out the template section in /WA ->New Aura -> From Template