I don't see anything in the Grimoire about the channeler being a hit-or-miss affair. So when I've acquired iron ore and use the channeler on it, I expect the raw iron drops. But frequently, the ore disappears and nothing is dropped.

Should that be happening?

No, this should not be happening. Is there anything regarding errors in your logs? I haven’t heard anything about a bug like this so I can only figure it out with some sort of log info.

Could be a mod conflict, I running the BenchMark II modpack, v 1.04 - and I've added some of my own mods to it. But let check the logs and see if there is anything interesting in them.

I didn't see anything in the main log where keywords "error" or "archon" occurred near a time that I was using the channeler.

I can try again, checking the log immediately after attempting to use the channeler to see if there is anything that might be helpful.

Absolutely nothing in the Logs:

End of logs, when pausing to test the channeler:

[19:10:07] [Server thread/INFO]: Saving and pausing game...
[19:10:07] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/minecraft:overworld
[19:10:07] [Server thread/INFO]: Saving Dank Contents
[19:10:07] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/minecraft:the_nether
[19:10:07] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/minecraft:the_end
[19:10:07] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/voidz:void
[19:10:07] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/edenring:edenring
[19:10:07] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/ae2:spatial_storage
[19:10:07] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/spectrum:deeper_down_dimension

No log entries during the gap from [19:10:07] to [19:10:34], I simply lost another minecraft:iron_ore block and got nothing for it. Oh, and I also expended 30 mana.

Additional log entries immediately after the test:

[19:10:34] [Server thread/INFO]: Saving and pausing game...
[19:10:34] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/minecraft:overworld
[19:10:34] [Server thread/INFO]: Saving Dank Contents
[19:10:34] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/minecraft:the_nether
[19:10:34] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/minecraft:the_end
[19:10:34] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/voidz:void
[19:10:34] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/edenring:edenring
[19:10:34] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/ae2:spatial_storage
[19:10:34] [Server thread/INFO]: Saving chunks for level 'ServerLevel[BM 1.04 - #2, custom]'/spectrum:deeper_down_dimension

Just looks like some native Minecraft or perhaps Textile Backup (part of the modpack) is just saving the game's state when I pause to tab-out and look at the log file.

Strange, I will test it out on that modpack and version shortly.

After doing some testing, I believe it's an error with one of the mods you added. I tested the channeler in both v1.0.5 and v1.0.4 of Benchmark II and it seems to work. I'll leave the issue open if you find anything else.

I was thinking it might be "Excavated Variants", but if things work in the modpack, then that's not the problem (at least not by itself).

I'll have to check out my extra mods and see if one of them might be the issue.