The problem seems to be with CSS overflow properties. Seems overflow property can hinder Lighthouse's ability to run Accessibility audit.
Reference: https://github.com/GoogleChrome/lighthouse/issues/11721
I saved your page as HTML on my local machine. When I tried the lighthouse audit for the page, I encountered the same error. I then created a copy of the page with all overflow properties removed from the source. Lighthouse was able to measure Accessibility now.
Note: The report for the new page also shows the specific elements where you have to improve the contrast ratio.