Unable to launch Boot Camp Control Panel

I just installed Windows 10 with Boot Camp. Once the install is complete, the drivers installed fine and a final reboot was completed without issue. Once the install was done I tried to launch the Boot Camp Control Panel and got the error:

"An error occurred while trying to access the startup disk. You may not have privileges to change the startup disk. Make sure you have administrator privileges and try again."

I have tried to run this as administrator (via File Explorer right-click and via cmd), tried rebooting, updating bootcamp/Windows, and may other way to get the Control Panel started. The only way to boot into MacOS is to reboot and hold down "option".

My thinking now is that this might be because I have FileVault turned on for MacOS. Anyone have any idea?

tl;dr

This is on my MacBook Pro Early 2015, 2.7 GHz i5, 8 GB RAM

Mojave 10.14.5

Boot Camp Assistant is 6.1.0

The BootCamp partition is 128 GB

Windows installer (from Microsoft's download page) is Win10_1903_V1_English_x64.iso

I've already done a deletion of Bootcamp and a then did a fresh install. No change in behavior. Not sure what to do now and any suggestion would be welcome.