A property declaration without READ/WRITE operations in the base class leads to a bug in setProperty for a different property (with READ/WRITE) in a derived class. Looks like the assignment is simply ignored - maybe because of a wrong sanity check.
Adding a second property declaration with READ/WRITE in the base class fixes the bad assignment.

In our situation we only need to check if a property exists, but of course one can argue that a declaration without READ/WRITE operations doesn't make much sense. Nevertheless it shouldn't break other completely valid property declarations.

The attached code demonstrates the problem.