I running a ryzen 3 2200 g with a Asus prime b450m a motherboard.

And core temp shows the core speeds jumping all over the place as Well as the voltage. Voltages neber go above 1.4. also sue I run prime 95 I get a error as one core will drop off and it's amramdom core every test. Any ideas on what's causin it? I'm Thinking it's my psu but not sure (psu is a corsair gs500)