I'm not able to set a filter for chemical channels. Whenever I put an item in the filter slot, it quickly disappears.
I'm able to set a filter on any other channel type. It's just the chemical channel that's giving me some issues.

I'm having the same issue. What was the resolution on this?

Oh sorry, the issue isn't actually resolved. Since I'm playing on the FTB evolution modpack, I thought it would be more appropriate to open the issues on the modpack's hub since it could be a mod compatibility issue.

Ah, did you try to put in an item with a gas/chemical in it? I made it not accept any items that don't have a chemical in it as it doesn't make sense to accept those as a filter.

I did, I tried with basic chemical tanks, one filled with hydrogen and the other with oxygen.

Is this on the latest version of the mod? Will take a look into it.

It's xnet Gases 6.0.0

Yup, exactly the issue I'm having. Tried setting filter with a loaded gauge dropper (containing Oxygen gas) or a loaded chemical tank... both were rejected. I'm also playing on FTB Evolution.

Also on xnet Gases 6.0.0