This is not really a bug but a possible oversight.
The new brick block sounds added in 1.16 are only applied to Nether Bricks, while the overworld Bricks (from clay) still use stone sounds.
For consistency's sake, I would expect the brick block sounds to be applied to all brick blocks in the game.
This report is invalid. This is a feature request not a bug, For feature request go here: https://feedback.minecraft.net/hc/en-us