We use this feature for drop chutes in the nether (and overworld) extensively on our server.
Definitely a defect in 1.20.40 and impacting our game play.
This issue still exists in 1.17.41.
I was testing a farm design that would shift the blocks under the stalagmites and then harvest the pointed dripstone with water dispensers. It would let the stalactites grow down to 7; and the player could harvest the stalactites manually if desired.
But by growing to 8 and stopping, this makes the concept unusable.
I can copy the design to a world download if that would be helpful.
I don't know if this is connected to the location changes in the trail ruin, but:
Looking at the 1.20.60.24 preview, I created a new world seed 3180463398101883184, and used the locate command to find a trail ruin. It sent me to -144 (Y) -192. This is over an ocean with no trail ruin nearby.
Trail ruins are at expected locations for this seed on Java based on chunkbase.com (i.e. 72 Y -840, or -152 Y 760)