When creating an addon the one thing that addon creators tend to want is custom blocks that can be mined with vanilla tools, however this bug breaks that.

Expected result:
The custom block should break at roughly the same time as the cobblestone block as the tools use the block tag to detect what block its breaking, this can be seen through custom tools that this tag used does in-fact work

End result:
The block breaks at a different time due to the block tag not being detected by the vanilla tools.