I have a similar problem, the overlay will not start, I've tried messing with multiple setting in AMD Radeon Settings, I also tried changing the hotkey but no luck. Note, ReLive feature works, doesn't turn off for me like it does for OP, for me just not the overlay. Both on desktop and in game (fullscreen)
Most of the hotkeys do nothing for AMD Radeon features, instead they just toggle my mouse on and off. Maybe I have some mouse software that has the same hotkeys already assigned, anyone wanna help me check/solve this?
Radeon Software Version: 18.8.1
Radeon Settings Version: 2018.0802.1822.33079
My Specs:
Operating System: Windows 7 Ultimate 64-bit (6.1, Build 7601) Service Pack 1
Processor: AMD Phenom(tm) II X6 1055T Processor (6 CPUs), ~2.8GHz
Memory: 8192MB RAM
Available OS Memory: 8192MB RAM
DirectX Version: DirectX 11
Card name: AMD Radeon R9 200 Series (290), Display Memory: 4095 MB, Dedicated Memory: 3050 MB, Shared Memory: 1045 MB