Verbosity level changes GeneralizedPCGSolver behaviour

During some experiments with the AMG preconditioner I noticed that the behaviour of the GeneralizedPCGSolver changed when using verbosity level >2.

level 1 produces a seemingly working result with output like

=== GeneralizedPCGSolver
=== rate=0, T=11.5603, TIT=inf, IT=1

the value of T changes but the rest is constant.

using level 2 results in non-convergence

=== GeneralizedPCGSolver
 Iter          Defect            Rate
    0       0.00256222
    1       0.00519744          2.02849

...

 6000      0.000353568         0.999963
=== rate=0.99967, T=3.44023, TIT=0.000573372, IT=6001

I have not managed to create another example which exhibits the same behaviour, which would be suitable as a test. Also I expect that all other solver can exhibit the same behaviour since the convergence criterion is handled the same way.