I'm playing a world created in 1.17 and updated to 1.18.1 and trying to find my first stronghold.  Eyes directed me to location of Stronghold found on my seed map for 1.18.  There is actually no stronghold at this location as it is an ocean biome, I checked underneath to be sure.

Seed -806031108147118925

1.18 location X: -5,244 Z: -204