Apparently it is only a visual bug. A recipe difficult of 405 (originally 375) got completed with a illustrious Insight (reaching 372 skill). The craft quality was R5 without inspiration.
Either way, this visual bug affects how the UI works as it increases the overall skill difficult, even being a master weaponsmith fully specialized to get the highest quality in weapons, the requirement skill can get to 425 which will cause you to not be able to reach the minimum req even for R4 quality, which players are used to send us craft requests and we have to ask them to send with R3 requirement instead.
Either way, this has been causing some confusion and distrust from people used to the system as they do not understand this bug and since there is no acknowledge of this issue, we have to spend a LOT of time explaining it.