Not using IMDB sometimes leads to incorrect results. For "Louis de Funès", Google finds a Bacon number of 3:

Louis de Funès and Terry-Thomas appeared in Don't Look Now... We're Being Shot At!. Terry-Thomas and Tom Aldredge appeared in The Mouse on the Moon. Tom Aldredge and Kevin Bacon appeared in Taking Chance.

The Oracle finds 2: Louis de Funès was in Les aventures de Rabbi Jacob (1973) with Janet Brandt was in Queens Logic (1991) with Kevin Bacon