PIE Root for English 'to kiss'

Hello All,

Please help me with a right PIE reconstruction for German
küssen 'to kiss' from where English 'to kiss' also derived.

The German küssen could be from a PIE *gWuhs- (PIE form that can
have a 'full grade' -> *gWeuHs-) see below the rules:

PIE to Proto Germanic:
-----------------------
*p > f
*b > p
*bH > b
*t > T
*d > t
*dH > d
*k > x
*g > k
*gH > g
*kW > xw
*gW > kw -------=> PIE *gW(e)uhs- > Germ. küssen <-> Eng. to kiss
*gHW > gw, w, g


... but I cannot arrive to match next the Greek kuneo 'to kiss'
(usually proposed as cognate) that seems to reflect a PIE *kWuhs-
(PIE *kW/u is reduced in Greek to k/u) but a PIE *gW/u will give
Greek *g/u (in a similar way)

PIE to Greek (Rules):
*kW/u > k/u -----------------=> Grk. kuneo
*gW/u > g/u
*gHW > kh

Thanks in advance for an explanation here (for sure is something
that I ignore),
Marius