since the firmware in my ebike engine Bosch performance CX gen 4 has been updated, I am noticing a strange beahviour, that is, when pedalling, the engine (or the rear wheel pawns) will not engage immediately.
[Similar to this][1]. Sort of a gap before the engine kicks in. The issue will show in a very perceivable manner when riding:

 1. When the bike is moving already, you stop pedalling
 2. The bike keeps moving
 3. You start pedalling again - this is when the defect is perceivable

Now, I am not sure 100% if this was happening before, as the firmware update, which added more torque, might enhance a beahviour which wasn't initially perceivable with less torque.

So I went to an authorised Bosch service support, and they got in contact with Bosch in Germany, who asked them to make some tests, but from their point of view there's no issue on the engine.
The man at the service thinks that the issue could be due to either:

 - A different freewheel pawns number in the rear speedhub and the engine ones
 - A low freewheel pawns number (31) in the rear speedhub. As for this, the man said that freewheel pawls in professional grade speedhubs can go up to 400, ensuring the "grip" is immediate without any gap when you begin pedalling.

I really don't understand why this "gap" was not noticeable before the engine firmware upgrade, but I am quite unhappy as for this feeling...

  [1]: https://bicycles.stackexchange.com/questions/22996/pedaling-not-connecting-right-away