The “shared mutex” method let SignalRGB co-exist with FanControl (CorsairLink plugin) for years. Recently this broke — SignalRGB now causes erratic temp readings from my Corsair Commander Pro when running alongside FanControl. Stopping SignalRGB fixes it immediately. HWiNFO64 + FanControl work fine alone; issue only appears with SignalRGB running. The CorsairLink dev confirmed the regression (his code unchanged since 2023): Corsair devices, SignalRGB, the shared mutex, and timing · Issue #300 · EvanMulawski/FanControl.CorsairLink · GitHub — please investigate!
This likely needs more than we can do over the forums tbh; I’d report the bug using the bug icon in the app (upper-right corner) or through this link so that the support team can follow up. We can look at links and investigate with the dev team on the back end!
I did post the bug report though the app just now. And I posted the same on your Discord server before posting here, but it got no attention except a reference to your “supported devices” page.
The issue is real, and it’s caused by SIgnalRGB, so I would appreciate your help to follow up on this! 
I suspect my issue is closely related. I also use Fan Control and my Corsair iCue Link Hub gets pinged by both SRGB and FC. When I stop SRGB, my system is quiet and respects my established curves, but as soon as I start SRGB fans rev and stay at levels FC cannot lower unless both programs are restarted. I’ve been trying to work through SRGB support and I’ve received several json patch files, but no solution yet.
The Discord server isn’t an official support channel, it’s driven by community volunteers. I’ve submitted the feedback, and also can confirm the Development team has heard about this behavior too. 