I'm trying to connect to a few sensors on the Nordic Thingy:52, and it fails with the following message: characteristic is not defined. The connection to the Thingy is established, but I can't get the notifications. I'm using the NRF52832 to connect to. In the Nordic documentation I found the 'EF68xxxx-9B35-4933-9B10-52FFA9740042' UUID, so I used it, replacing the xxxx by (f.i.) 0201. Any idea about the cause?