<img src="checkin.png" alt="Morning group check-in">
I’m not sure why you expect a different image path. Perhaps you had an image render hook that did something different, or you added an image render hook, or something.
As always, a link to your repository would simplify troubleshooting, and save us both some time.
OK, I just rebuilt using 131, 132, and 134, and it looks like the difference is in the way the post summary is generated (completely different summaries under 131/132 vs 134).
At first I thought the cut-off points got modified, but it looks like only the type returned was changed (to HTML). I think we can address that on our end by adding appropriate summary markers, so it will cut off earlier.
Great idea. In my view, relying on an “automatic” summary is unwise. I would always define the summary using the <!--more--> tag, or by defining a summary field in front matter.