I've seen this bug reported with Optifine/Optifabric to a but to report it in a more concise way, I'll do so here.

As far as I've seen, CIT replacements are bugged in the inventory.
Strangely enough, they seem to render with their appropriate cit textures elsewhere.
Screenshots demonstrating this are below: (if it works)

the Redstone in the Hotbar appears with the regular default texture, however, In the player's hand (both first and third person), and as a dropped item, the texture changes following the CIT of the resource pack

additionally, and possibly related, food animations also don't render in the inventory.
through basic testing, the type of CIT doesn't appear to matter, just the fact that the item has changed.

Thanks for screenshots

CIT reserwn adds such a pouch or what is it?

Not they simply use a pack that has CIT in it
This is a duplicate of #9 and #20
It can partially be resolved by #16

fixed soon