"Graphs" button on the toolbar becomes inactive after selecting a graph type in the menu

Scenario:

1. Open "data/samples/FASTA/human_T1.fa".
2. Click on the "Graphs" button on the toolbar.
   Expected result: a graphs menu appears.
3. Select "GC Content" graph.
4. Add a label to the graph: hold Shift and click somewhere on the graph.
5. Click on the "Graphs" button on the toolbar.
6. Select "GC Content" graph.
   Expected result: the opened "GC Content" graph is closed.
   Current result: the "Graphs" button on the toolbar becomes inactive. The menu with graphs also ignores mouse moves. The graph is not closed.