Looking at the profile, it doesn't really tell me anything.(perhaps I am looking in the wrong place)
Something to note. Once I used the debugger it stays slow, it will show around 60 fps on the playground again. But my pc won't stop being slow until I close the tab that has the playground in it.
Here is the profile and a picture of it.
profile.json
My Task manager doesn't really tell me much either, since my CPU is only around 20%