Is there a limit on the amount of source folders allowed in the package view?

Been stuck on this for a good part of the week now, I have an automatically generated .classpath file that has quite a large number of source folders listed within and said source folders will simply never show up in the package explorer when the project is loaded. Manually adding the source folders one by one reveals that after a certain number of source folders are added all of them will simply disappear from the explorer. Is this intended or a bug, and if this is working as designed, is there an option to turn it off?

classpath file

Package Explorer (Notice how the "jdk" project has no triangle to expand the view and show the source folders, to Eclipse it's as if the project is completely empty)

Start by reproducing the behavior in the Package Explorer with the automatically generated .classpath file shown in the issue, then compare it with source folders added manually. Determine whether a source-folder limit causes the project to appear empty and identify the relevant Package Explorer or classpath entry point. Done means the limit is explained and the reported behavior is fixed or clearly documented.

Written by the indexing model from the issue text.