I have found that the following blocks can't be picked up even with a silk touch pickaxe. When mined they drop nothing.

Iron beam
bolted iron beam
steel beam
bolted steel beam

The iron beam junction and steel beam junction work fine and drop themselves when mined.

Minecraft 1.18.1
Forge 39.1.2
mapperbase-1.18.1-4.0.0.1
embellishcraft-1.18.1-5.0.0.1