1600 dpi and 1,8 sens seems a bit too much.
dpi is mostly up to preference but yours is so high that I really think that it will cost you control in the end.
Try to go down to 1600 and 1,2 sens or something.
And no it's not weird that you're doing good with mouse.
2/3 of your skill lies in your taphand and your perception so it's natural that it suddenly feels as if mouse was easy but you just improved on other things.
dpi is mostly up to preference but yours is so high that I really think that it will cost you control in the end.
Try to go down to 1600 and 1,2 sens or something.
And no it's not weird that you're doing good with mouse.
2/3 of your skill lies in your taphand and your perception so it's natural that it suddenly feels as if mouse was easy but you just improved on other things.