Pairing Back Beat Fit 3200 with Sandisk Sport Plus

Hi, has someone any experience with connecting the  Plantronics Back Beat Fit 3200 with the Sandisk Clip Sport Plus ? Just tried everything, also installed the lastest firmware version 20.1.     Sandisk Sport Plus detects the  Back Beat but the pairing don’t work.  Someone has a suggestion?  Also tried to disconnect all the other  wifi and bluetooth in the house.

Thank you for helping me.