Reproduction steps:
1. Open the attached project "New Unity Project.zip";
2. Open the "main" scene and enter a play mode;
3. In the Player settings, uncheck Dynamic Batching. Note that the number of batches reported on the Statistics window increases from 4 to 11.
4. Exit play mode. Note that the Dynamic Batching reverts to the enabled state as expected.
5. Enter a play mode again and open the Frame debugger window.

Expected results: as the Dynamic Batching is enabled, the Frame Debugger will show it and the number of batches in the Stats window will decrease to 4.
Actual results: even if Dynamic Batching is shown as enabled, it is not working and the Frame Debugger skips it, the Stats windows is still showing 11 batches.

Workaround: After exiting a play mode in step 4, uncheck and re-check Dynamic Batching in the Player settings.

Reproduced on: 5.6.3p4, 2017.1.2p2, 2017.2.0p1, 2017.3.0b8, 2018.1.0a3.