Low HRV even when TSH normal

Hi all! I’m wondering if anyone has a low HRV even when their labs are normal and if they have done anything to improve it. Before hashimoto’s my HRV was 45-60 ms (average for three years). Since being diagnosed, my HRV has consistently been 10-17ms (average for two years), even when I’m medicated. I am 30 years old and a runner but these numbers concern me. I’m planning on bringing it up to my doctor but just curious if others have had a similar experience