Seems to be a bug in restock_help command (wow classic):
when there are crafted items on ignored chars, this command will report that "You already have your max restock quantity", while normal crafting operation will queue the item correctly.

Reason: in TradeSkillMaster\Core\Service\Crafting\Core.lua
this line: local neededQuantity = TSM.Operations.Crafting.GetRestockQuantity(itemString, private.GetTotalQuantity(itemString))

GetTotalQuantity() returns count of an item on all characters, it does not take ignored chars into account, unlike the crafting operation. You need to substract quantity from ignored chars as it's done in Crafting\Queue.lua::RestockItem().