title: Browsers became extremely slow with jupyter lab
body: <p>I was working in jupyter lab on a server through a FF 72 for 3 days and it was normal. But after I cleared all cell outputs it instantly became very very slow.</p>
  <p>Mouse reaction, keyboard reaction times reach 2-3 seconds. Scrolling is more or less okay, but clicking, typing are way too slow for normal work.</p>
  <p>The notebook itself is not big (maybe 50 cells, cells are also not big), only python text, no graphs.</p>
  <p>I've found this <a href="https://github.com/jupyterlab/jupyterlab/issues/1639" rel="nofollow noreferrer">jupyterlab issue 1639</a>  but it doesn't suggest any solution. Tried Chromium - even worse.</p>
  <p>Any known solutions? Workarounds?</p>