abacab
What if a recent Microsoft update has affected something the only the newer Cakewalk has a dependency on?

That wouldn't surprise me at all, given that Native Instruments' Kompete Kontrol worked fine with CbB before the 1803 update, but afterward, the keyboard displays can't communicate with the plug-in.
 
Interestingly, Komplete Kontrol causes Studio One to hang/freeze if you try to use it as a plug-in. The only fix is to remove SO's ReWire capabilities in Advanced Preferences.

abacab
What if a recent Microsoft update has affected something the only the newer Cakewalk has a dependency on?  That could explain why the older Sonar is not having the same issues.  It's possible that CbB has been updated to use newer MS programming libraries.  This is just speculation, but I was thinking about what the possible reasons could be.
 
Did you apply the July MS patches (released 7/10) to your system, and was CbB stable before that date?

I think there is a likelihood of this.  My desktop was W10 1803'd three days ago from 1709.  I thought I'd got away light - no change to my sound driver which others had endured, and just the usual re-authorisation of XLN Addictive Drums to do.  It seems more than a coincidence that all was running fine with CWbBL before the 1803 update.  I wonder what change is causing this?