I have noticed that the numbers on the arcane panels do not match.
example: take the "Cascadia Accuracy" arcane (I have 1 fully loaded and looking to load another)
Cavalero browse shows that I have 21 arcane that I purchased.
Onboard Ship Arcane show I only have 20 : was showing 21 until last update.....
Loid Arcane Dissolution (where I first noticed it) shows 20
I think Cavalero is right; other sources show same type of numbers when you acquire them.