there's a variance between plants... some take longer.. maybe the seed was buried a bit deeper or something a bit more substantial in its way to break ground.. lots of possibilities.
just make sure the substrate doesn't dry out.. it's wise to follow a good dry/wet cycle to promote preferred root growth early on, but with seedlings if the root isn't deep, you need to make sure even the top layers remain moist. (first 3-5 days or so)
the seed will pop open within 24-36 hours, but then has to burrow down and up... have faith... if it's viable, it's coming. if it is not viable, it's out of your control.
i like to make sure the seed is 'horizontal' .. i cant always recall which side the taproot pops out of, so horizontal ensurees it can easily burrow down, while also forming a solid lever with the terminal bud charging toward the surface. even if upside down, they mostly make it, but i've seen some get flipped under ground and require a little manual effot to re-plant it in correct orientation. ... i've seen a tap root get stuck in a shell and just coil around at top of substrate in the shell.. didn't realize until the seedling randomly died.. noticed after the fact is it was out of sight. don't bury too deep, and use some substrate that's nice and fluffy... will get faster sprouts within what you can control.