ltsgraph visualization issues on macOS

[volkm]

I am running mCRL2 (version 202307.1) on a Macbook Pro with macOS version 12.7.1.

When displaying a graph in ltsgraph I can see the nodes and the action labels but not the transitions (arrows) in-between the states (see attached screenshot). The nodes are also missing the colour.
The same issue is present when building from the master branch. Using an older version 202206.0 of mCRL2, ltsgraph works as expected though.

[mlaveaux]

I can now after upgrading to Qt 6.6.2 reproduce the same issue on the build server (mac mini 2018) with Sonoma 14.4. Apparently for Matthias the issue has been resolved on their new mac book,