Sculk Catalyst and Sculk Veins only drop when broken by Silk Touch hoe

In survival, sculk catalysts and sculk veins will will not drop when mined by any silk touch tools other than  the hoe. I discovered this when using a silk touch pickaxe. 

Expected Result:

Sculk catalysts will drop when broken by any silk touch tool, although it might take longer.

Observed Result:

Sculk catalysts are destroyed when broken by any silk touch tool other than a hoe.