On the latest version, 1.6.77, I'm having issues with Thermal Expansion in and this mod.
Any kind of non-vanilla ingot turns into Pulverized Iron.
Any kind of non-vanilla gear turns into an Invalid Item.
Any kind of non-vanilla plate turns into a Pulverized/Blend/Dust of whatever plate it was.
Pyrotheum dust turns into Pulv Iron, Cryotheum dust and Blizz powder turns into Pulv Gold.
Aerotheum, Petrotheum, Mana Dust, Basalz Powder and Blitz Powder turns into an Invalid Item.
That's all I've tested.

I should say, this was never something that happened with the previous version.

Ehh, could be an issue that I caused, the pack I'm playing doesn't by default have the mod in, I added it in on my own, so I could've screwed something up there? Idk.

That could very well have been the case. Could you try reproducing the issue in a setup with just Dank Null and Thermal Expansion to check if it persists?

If it doesn't I would recommend asking in the modpack's discord or support channels.

I just tested this in the pack i play and i cant re-produce, all the copper/silver/lead/yellorium etc all crush to there respective dusts aok.

Just tested it out with only Thermal Expansion and Dank Null, problem is still happening.
Mods

No idea what you're doing, but I can't reproduce this.