/search/issues returns different results than /org/repo/issues

There are two issues in a repository that are not returned by the Github API and I’m trying to figure out why.

https://github.com/opencadc/vostools/issues?q=+is%3Aissue+is%3Aopen (41 issues)
vs
https://api.github.com/search/issues?q=repo:opencadc/vostools+is:issue%20is:open (39 issues)

Both missing issues are open & look pretty regular to me (issue id 138 & 42, I can’t link them because I’m a new user here and can only provide two links per post)

Any ideas?