Godot Web Performance influenced by Local Godot editor open-closed

[Michel de Messieres]

We do web export and to measure performance I'll open Chrome on my Mac with frame rate limit disabled. So I test my godot application and perhaps I get 70fps. We're on Godot 3.5.

But if I open Godot in the background (just the application, not any specific project) now my performance has jumped to 550fps. So I'm at the project selection screen and have not opened any specific project.

If I quit Godot this is dropped back to 70fps. So it's reversible.

I set up my own clock timer to validate and compared to Godot's fps counter and all are consistent.

So I'm wondering what exactly is happening here? Is it possible Godot is launching some critical GPU driver component for example? And this 'helps' the web program? But if I quit Godot we lose it. I can see how this might be missed because if a test was conducted with Godot in the background a developer may have a false assessment things were setup correctly.

I am quite grateful if anyone has an insight. I am just doing some further tests trying to figure out what basic logic error I could be making on our side.