laravel-forum | lean forum package designed for quick and easy integration | Collaboration library

I recently moved a Laravel website to a different server with the same setup (slightly different versions of php, mariadb, etc.) and have run into an interesting problem.

I'm using the package Team-Tea-Time/laravel-forum (formerly riari/laravel-forum) to provide message board functionalities. In the forum every thread has a link to get to the newest post, which worked fine before the move. After the move those links lead to the oldest/first post instead.

The functionality is part of the Thread model, specifically the function getLastPostAttribute().

When trying to get to the bottom of this, I realized that the orderBy on the posts relationship is simply not having any effect. No matter what attribute I sort by (e.g. created_at, sequence) and which sort direction I request, it's always the same post order and the same first post being returned.

Example of a thread with 1811 posts with different timestamps and sequence numbers:

Ordering by sequence ASC works correctly, the first post being the one with the smalles sequence number. This is however also the default order of that relationship (see Model).