Aircraft doesn't fly as it did before

Hi,

When I got the B200 I was very impressed with how it flew. What I loved most was the way the aircraft moves around even when you do nothing, unlike the default aircraft, it wasn't  perfectly stable all the time. So therefore, you have to make corrections constantly. But when I fired up my plane today, this feeling was suddenly entirely gone, the aircraft was perfectly stable and I barely had to do anything to keep it straight while before I had to correct constantly. I am pulling my hairs out over this. Is there any setting I could enable for this?

Please help me.