Might just need to fiddle around with afterburner abit.
on the Afterburner settings menu make sure to tick/select:

• Force Constant Voltage
• Extend official overclocking limits
• Disable ULPS
• Unofficial overclocking mode "without PowerPlay support" (i think this is the most important one)

Could also try uninstalling/deleting the MSI Afterburner App and folder.
Another thing worth trying is enabling/disabling Overdrive in the CCC.