Is Steam gameplay different than original?

I recently bought the definitive edition on Steam because I haven’t been able to find my hard copy for years and I wanted to play online. For some reason though, I don’t have certain research options. For example in aoe2 conquerors I had the option to research cartography from the market but I don’t have that option on my Steam version.

Initially I thought it was because I played with the Conquerors expansion back in the day and maybe it’s from the expansion, but isn’t the definitive edition...definitive?

Any ideas? I don’t know if it’s something I can fix with dlc or mods or if I literally don’t have the ability.