alt image tag not loading

I have alt tags on images. The “alt=…” is not loading in the source code. Here’s an example: https://lazyacresnorth.com/2010/12/05/brews-of-the-season/

I use a 3rd party plugin for SEO but it doesn’t touch images. I’m using a 3rd party theme but it doesn’t, or at least I can’t tell if it’s removing the tag.

Any ideas on where/what to check?

Thanks for your help!