Jayce's Mercury hammer First auto bug

I'm a jayce main for some time now , lately i noticed two weird bugs regarding his first auto in mele form, more specifically : every time I try to change to mercury hammer just when the auto attack animation on mercury cannon starts jayce will perform a ranged auto attack with his hammer applying the bonus magic damage, that auto attack doesn't appear to connect to the target , Although that's very hard to pull off as it needs a lot of timing , it can be abused early in lane for that free bonus magic damage i captured it here: http://sendvid.com/luvqjta3

The other thing i sometimes notice is that after jumping in with mercury hammer issuing an attack command usually fails and you need to re issue it , some other times that auto seems auto of sync and its definitely much slower than a normal one but i don't know if that's how it supposed to be so you can use your hyper charge W or e auto cancelation in order to get the maximum dps in mele form.

I have been noticing the first bug since the start of this season and i have been noticing the second one since mid season 4 sorry for my English I'm European.