https://sourceforge.net/p/openmsx/openmsx/ci/HEAD/log/?path= doesn't show all authors (e.g. the 2nd commit of that list)... why not? Only Wouter seems to be shown of those latest commits.
(That author would be mostly me ;-)
I checked the project's git log via cli to see how I might reproduce this, and I was able to reproduce this by changing some of the characters in my git config's email address to include uppercase. Which might explain the issue for commits like Manuel Bilderbeek's, but it won't explain why it's missing from user's like Patrick van Arkel's (note, author shows on individual commit page, but not on the "history" page like the user links to in initial report).