Opening Vimium Options from within a container presents empty options

Describe the bug
When using MultiAccount Containers, if Vimium's Preferences page is opened from anything other than the Default container, the options page opens but all the fields are empty, and the "Show available commands" link doesn't work.

This issue does not occur with other extensions - for eg., Gesturefy's preferences page opens fine with all the right content in it, even when opened from within a Container. And the same is true for every other addon I tried this on.

To Reproduce
Steps to reproduce the behavior:

1. (With Multi-Account Containers installed,) Open a new tab in a Container (for eg. Work)
2. Open about:addons in it
3. Scroll to Vimium, open its three-dot menu, choose Preferences

Expected: My previously entered preferences eg., my excluded URLs, my many mappings, etc. should be shown.
What happens: The excluded URLs list is empty, the mappings are empty, and the Show available commands link doesn't work. The Show Advanced Options button is missing, instead in its place, just a blank rectangle is shown.
Re-opening the page in a "No Container" tab properly displays all my pre-existing preferences, but opening it in any Container shows only empty fields.

Browser and Vimium version

Firefox Developer Edition 86.0b
Vimium 1.66

Start by reproducing the issue in Firefox Developer Edition 86.0b with Multi-Account Containers, opening Vimium Preferences from a non-default container. Trace the preferences page and container-specific loading behavior; it is done when existing excluded URLs and mappings, the available-commands link, and the advanced-options control display correctly in a container.