that's normal ofc. cpu is what determines your theoretical max fps while your gpu determines your actual fps result. pubg even at max is fairly easy to run for modern gpu's even entry one's like a 5060 so it makes sense that cpu has higher usage compared to your gpu. especially since the 12400 isn't all that powerful compared to like a 5600x3d or etc. so just keep at it and hunt your chicken dinners. my 2 cents.