There are two ways to index patients in PT: index(patient) to add or update a single patient to/in the index, and and reindex() which updates all patients
Apparently starting from some Solr version our index() is broken and changes are not committed to the index. Upon server restart reinex() is called and all patients get added to the index, but new changs are no committed again.
The issue seems to be that our index() does not do this.server.commit(). Probably it used to work without it, but it does not work now. When it is added, everything seems to work as expected.