Tag parameter breaking web pages

I’m not sure when this started, sometime in the last month or two, but suddenly all the pages that use display-post with the tag parameter are broken. These pages also use the category parameter, but I was able to isolate the problem as being the tag.

We’ve made no changes to the page themselves or to the tags and slugs they’re referencing, and they worked for years prior. There are posts with these tags.

e.g. https://justharvest.org/get-involved/take-action-to-change-public-policy/ https://justharvest.org/get-help-during-the-coronavirus-pandemic/
(These pages use different tags.)

We’re using version 3.02 of the plug-in.

Please help!

-Emily

The page I need help with: [log in to see the link]