BBT chart woes

Dawn
So I bought a new basal thermometer.   It's metric. Since I started using it, my chart is inaccurate and unreadable, as my temp is usually around 34.0, and Glow changed it to 35.0.  This is frustrating as my opk results were a bit confusing, and I did have a temp jump to 34.9 on Sunday.  Is anyone else having this issue?