Linux thread priority/nice set to lower-priority than normal starting from the second benchmark.

I use nice -n -1 when running the benchmark to minimize the effect of background processes on the system (on Linux). I am using NativeAOT 9.0.2 with the InProcessNoEmit toolchain. I observe that when running the first benchmark, the nice value is expectedly -1. However, starting from the second benchmark method, the nice value becomes 10, which is low priority. It is quite surprising to me, but I didn't find where the thread priority is changed.