Question about Philips Series 8000 AMF870

Is it possibly due to the standard 2.4 GHz interface? See instructions on page 14 under the "Laser signet". It worked for me without any problems, but I had the same problem with a timer app and then had to set up a second interface with 2.4 GHz instead of 2.0 GHz. Unfortunately I am not familiar with this, so my tip should have nothing to do with it.