Black dot on my active watch 2 at the bottom

[Kevinji]

A black dot is appearing after the workout with sluggish functioning of top right/back button.

Does this make my watch defective?

[AMPK]

Take it to service center

[cs-member13]

Dear Samsung Member,

Greetings from Samsung Customer Support!

We apologize for the inconvenience caused to you. We request you kindly visit the service center for the physical inspection of your device. To check for the nearest Samsung service center kindly click on the link:- https://www.samsung.com/in/support/service-center/

Thank you for writing to Samsung.

Warm Regards,
Samsung Customer Support