No filters returned from filters.getAllowingFilters after adding filter

Environment

• adblockplusui fork#sdk-poc
• webext-sdk#3f08a28e

Steps to reproduce

1. Add the following code to the extension's background page:

EWE.filters.onAdded.addListener(async () =>
{
  let tabs = await browser.tabs.query({});
  for (let tab of tabs)
    console.log(EWE.filters.getAllowingFilters(tab.id));
});

window.addAllowingFilter = () => sdk.filters.add("@@||example.com^$document");

2. Run addAllowingFilter() in background page console.

Observed behavior

Empty array is logged.

Expected behavior.

Array containing @@||example.com^$document is logged.