watchdog error, sleep and lockscreen freezing, and stable under some load tells me either the cpu isn't getting enough voltage if it's manually oc'd, or there's some bios or os powersaving thing malfunctioning.
reset bios settings, especially if you've done any overclocking. turn off any core boost or other variable core clock powersaving amd/intel specific 'features'; these are almost always unstable in my experience.
if that doesn't work, double check all power cables are properly seated in both mobo/component side and psu side if it's modular. make sure ram is seated properly. if you're on windows make sure you're on high performance mode. i can't think of much else to check without more info. good luck!
i mean, it depends on the cpu and your workload. i have a 1st gen ryzen 1500 and amd rx580 gpu, so yeah, my cpu is the bottleneck in this build. i do have it slightly oc'd and it def helps a bit keep it smoother gameplay especially when travelling fast in game and new areas need to load up. the pop-in and small frame dips are a bit more noticeable on stock clock speed. did i really need to oc it? nah. but i like to squeeze every last bit of capability out of my hardware just for the fun of it, too.