Might be related to the Razer Game Scanner service that’s reporting errors (can turn it off), or your Razer peripherals, depending on their driver software.
Low FPS with Razer Chroma Software Installed
We have seen reports of dramatically lower than expected FPS with Razer Synapse/Chroma installed. Typically players will see their FPS stuck between 15-30 FPS while experiencing this issue. If you have your Chroma device, enable Chroma effects for Overwatch, or uninstall the Razer Synapse/Chroma software and reinstall the newest version of Synapse 3.
If you no longer have your Razer device, follow the steps for the Razer blackscreen issue .