This appears to be happening with a few items. Two of note are the chest pieces for my Galacticraft space suits. My tier 2 and tier 1 chest pieces cannot be extracted from storage by using the remote interface.

To replicate, I insert them into storage and attempt to remove them. no interaction.

I then go to the chest where they're stored and pull them out without any issue. Drop them back in and attempt to extract via the remote = nothing.

What version of the mod are you using? In version 1.2.6 there was a fix for something related to this,

https://minecraft.curseforge.com/projects/simple-storage-network/files/2573911

Have you found any other items or is it just that armor?

1.2.8 just came out, it should work fine in that version but ill leave this open for now https://minecraft.curseforge.com/projects/simple-storage-network/files/2599746

I'm on 1.2.4 still. can't confirm if the update fixed this as I'm not able to update my pack right now.

I have noticed a few other items since that won't come out. My Astral Sorcery Resonating wand and aminotaur axe from twilight forest,

Was fixed in 128 i just forgot to close this. Also loooks good on latest version as well https://minecraft.curseforge.com/projects/simple-storage-network/files/2608694