User Search fails to find certain substrings

[Ceiridge]

Describe the bug

This is a bug that is apparently not always reproducible, meaning it might occur or it might not, but it does happen. This was experienced on test server 2 while testing the following pull request (see discussion): https://github.com/ls1intum/Artemis/pull/7789#issuecomment-1859089163

All users in the test servers have the format Test User X Artemis, whereas X is a number. Searching for Test or User did not yield any results, but searching for Artemis worked.

To Reproduce

1. Use the search functionality anywhere on a test server, preferably when creating a group chat
2. Search for different substrings
3. Have (bad) luck that it breaks

Expected behavior

Searching for any substring of a user should return the respective users, i. e. the search should work.

Screenshots

Which version of Artemis are you seeing the problem on?

6.7.3

What browsers are you seeing the problem on?

Chrome, Safari, Microsoft Edge, Firefox

Additional context

Copied from the discussion in the PR: I guess it has something to do with MySQL/Postgres and the way the search queries are written

Relevant log output

No response

[julian-christl]

Have you ever checked the network response? Whether a request was sent and what the result was?