Have a similar situation: booked on AGP-MAD-CDG IB flights and a connecting flight (separate ticket) on AF CDG-HAJ.
Can I check my luggage already in AGP through to HAJ, inspite of a separate ticket?

There is never a problem on *A oif itīs a LH, LX, SN or JP agent. But dunno about IB.
Am OW emerald btw....