it'll be your version of windows that your running 1909 is pretty old now, some of windows most upto date updates will cause all sorts of problems if they try to install on 1909, they wont know any diffrence and will install to it, have a look at updating windows to 20h2 os build 19042.867, thats what i run and its stable as a rock, which gpu driver do you have too as the latest version may cause problems with windows version 1909 that you have (the latest nvidia driver is 465.89) you may be ok with earlier drivers but again if you have installed the latest on a old version of windows that will cause yet more problems.
have a look at updating windows first, you may find your oc settings you had before are not the problem