Full-Size Images Displayed as Tiny

Suddenly find myself in WP 4.7.3 and Thesis 2.2 to beat Friday server upgrade. (Two days ago I was 3.1 and 1.8). Despite posting links to full-size images in the POST IMAGE and THUMBNAIL IMAGE boxes, I get thumbnails (or too-small images) on the home page. Full-size images linked within posts (in tables that specify the image size, no less) are displayed as tiny. I want full-size images beside the homepage teasers (for at least the last 10 posts), and within the full posts.

Perversely, the images that are supposed to be small (links at the bottom of each post) are now too big. No idea why.

Hoping someone here can point me to a fix.

Thanks for any help!