Clock skew alerts exceeding threshold value

HI,
Out of interest, physical or virtual (VE) F5's?
NTP Config needs to be many 4+ I normally work on 4-6 in most deployments.

My though is if this is a VE, it might be showing that the underlying host has the issue not the f5 and for example if its been vmotioned on a vmware platform the first the os does is get host time before the NTP service can kick in and try to fix it.

If the host is to far out the ntp service just wont be able to bring it back into scope, which is possibly what you are seeing.