It looks like the story with ELM327 v2.1 continues, we already have 2 complaints from customers who purchased an adapter claimed to have ELM327 v2.1 inside. But in fact, it seems, they have some counterfeit chip that doesn't work properly and even doesn't support commands supported by old good ELM327 v1.4 and v1.5 (even china clones).
If we check it using a terminal and ATI command, we will see v2.1:
So it tries to convince us it is fair ELM327 v2.1. So what is the problem then?
First problem is that it doesn't recognize some commands that are supported in all previous versions of ELM327 and must be supported in 2.1 too. For example (the list is not complete):
Another problem is that it often behaves not adequeate. For example, instead of waiting for 200 ms for ECU response, it returns NO DATA immediately after the request. This is how it looks like for the end user:
So in summary, this seems to be very buggy product (even for china clone) and we strongly not recommend to use it.
At this moment officially supported (and recommended) adapters are OBDLink SX/MX, ELS27 and CanTieCar v3.