Some tyres may just give a different feel. Back in the day I had a Honda Civic Type R which had Bridgestone as standard. I changed for some Toyo's after 12k miles. The car tramlined like mad, so after 5 days I went back and had some Bridgestones put back on and it was perfect again. I know they would have settled down, but frustration got the better of me, and at the time no one could say what caused it.

I'm sure it will be right soon.