This is strange.
We have only noticed this since upgrading to Jira 10.3.11
It is an API we do not user regularly, however, we are not able to search for users beyond the first 100 available users.
for example
If I user the following:
/rest/api/latest/user/search?username=.&startAt=0&maxResults=100
I will get 100 results. However, if I were to increase the startAt to 99 for example I get a single result where the user is equal to the last user in the first call (the 100th user)
I have tested this against issue search and I do not get this problem. It seem that the response is different for Issues as they are paginated.