Valid Placement Bug

I noticed when using the Block valid placement condition for a block that replicates weeping vines, you can still place the block anywhere, and only when the block receives an update is the offending block broken. This isn't really an ideal way for the block to check if it can exist, and I was wondering if another method or code segment could be used to check if the block can be placed before placing it by the player.

Edit: Ok actually nevermind? I definitely had the issue where the thing would just break, but now I can actually only place the block where it is valid. I'm not sure what caused that to be a bug but it has been resolved ig.