MuTect2 high insertion counts?

Hi Folks

I am using Mutect2 to analyze blood vs. FFPE tumor samples (breast cancer).

I am getting (what I think are) unusually high insertion:SNV ratios - the ratio is between 2:1 and 3:1, thus high numbers of insertions.
The deletion:SNV ratio is between 0.1:1 and 0.25:1.

I was wondering if anyone else had experienced something similar or had any advice / comments?

Best regards,

Fourie