Windows 10 issues after Dec.2017 upgrade

Hello,
Every since a big update in late Dec. I have had an issue with explorer becoming unresponsive, most notably nothing happens when you click the start button, other things become sluggish and flaky also. I have found a temporary fix but I would like to know what is going on. I can ctl+alt+Del and get into task manager go to details right click explorer and analyze wait chain and end task on Svchost.exe underneath syncsettingshost. usually at or near the bottom of the list.




The system will work normally for a while but eventually the issue returns. I have several machines having the same issue.
Any ideas?
Windows 10 x64 Ver. 10.10.16266

If these are all machines with AMD processors it is probably due to the recent updates associated with the meltdown and spectre CPU problems.

There is a new update that might help:

Microsoft patches its earlier Meltdown patch for AMD PCs

The other mackine is an intel x99 series.