`aria-expanded` property seems to be missing, but appears in devtools

I just started using cypress-axe, and the very first error I'm getting is this:

Required ARIA attributes must be provided
=========================================

<input type="search" autocomplete="off" class="ant-select-selection-search-input" role="combobox" aria-haspopup="listbox" aria-owns="rc_select_1_list" aria-autocomplete="list" aria-controls="rc_select_1_list" aria-activedescendant="rc_select_1_list_0" readonly="" unselectable="on" value="" id="rc_select_1" style="opacity: 0;">

Fix any of the following:
  Required ARIA attribute not present: aria-expanded

However, when I use devtools to inspect the element in question (a select from Ant Design), I can see that aria-expanded is actually there:

This problem is reproducible on all the Ant select components on the page. I'm running cy.checkA11y well after the page has fully rendered, so I don't think it's an issue of "the property hasn't shown up yet". The property appears to be there, but cypress-axe is not seeing it for some reason.

Reproduce the report with cypress-axe's cy.checkA11y against an Ant Design select and compare the DOM seen by the accessibility check with the element shown in DevTools. Trace where aria-expanded is handled or lost; done means the reported error is explained and the behavior is covered by a regression test.