It appears that an MS hotfix applied to the Nov 19 RS1 and the RS5 builds break the UWF wireless exceptions we previously used. Below is a potential workaround.
The root cause appears to be an MS update that prevents the creation of the C:\ProgramData\Microsoft\wlansvc\Profiles\Interfaces folder while the write filter is on. The workaround is to create this folder while UWF is off. The following steps/commands can be used to create the required folder and add the UWF exclusions for keeping Wi-Fi settings with UWF enabled:
Install WDA 220.127.116.11 via Wyse Management Suite (WMS) or locally in Admin Mode
Login as Admin on device
Open Command Prompt with Administrator rights