grouping does not work cc2018 v12.1

I couldn't find anyone else reporting this problem, but grouping clips does not seem to be working for me. I select several clips (same layer or different layers) and hit CTL+G, or choose Clip/Group from the menu, or right click & choose Group. The option is then grayed out, but when I click on a clip within the group, only it highlights and only it will move when I drag it.

Am I doing something wrong?

System Model HP Z6 G4 Workstation

Windows 10 Pro for Workstations 64-bit

Version 10.0.17134 Build 17134

Processor Intel(R) Xeon(R) Gold 6154 CPU @ 3.00GHz, 3001 Mhz, 18 Core(s), 36 Logical Processor(s)

Installed Physical Memory (RAM) 96.0 GB

Adapter Description NVIDIA Quadro P5000

Driver Version 23.21.13.9174

Familiar Driver Version: 391.74