Yeah this is the reason most probably. After the UI update I had the exact same problem. After 2 days of search for solution I finally found it. When it tries to open with discrete GPU it just blinks and doesn't open. I can only open it with integrated GPU. And you definitely have to use DRI_PRIME=1 argument for every game to open them with dGPU. It is kinda annoying but it's only solution for now until Valve updates it.
Yeah this is the reason most probably. After the UI update I had the exact same problem. After 2 days of search for solution I finally found it. When it tries to open with discrete GPU it just blinks and doesn't open. I can only open it with integrated GPU. And you definitely have to use DRI_PRIME=1 argument for every game to open them with dGPU. It is kinda annoying but it's only solution for now until Valve updates it.