Opening a new tab with this extension enabled is very slow

[peterhoeg]

With this extension enabled and "New Tab Override" it is super slow to open a new tab in firefox. It takes several seconds.

Chrome with browserpass (and "New Tab Redirect") does not have the same problem.

With both firefox and chrome, the new tab page is hosted on localhost.

Disabling either the browserpass or "New Tab Override" extensions makes opening a new tab instantenous.

General information

• Operating system + version: NixOS unstable
• Browser + version: Firefox 83
• Information about the host app:
  • Package manager
  • Version: 3.0.6
• Information about the browser extension:
  • How did you install it: addons.mozilla.org
  • Version: 3.7.1

Exact steps to reproduce the problem

1. Install and enable the "New Tab Override" extension from addons.mozilla.org

2. Install and enable the browserpass extension

3. Open a new tab (Ctrl-T)

What should happen?

The new tab should open almost immediately.

What happened instead?

Opening a new tab takes anywhere between 3 and 6 seconds.

[peterhoeg]

Pointing at an external URL (such as https://www.google.com) is also much slower with this extension.