Stairs or steps? You mentioned one in the title and the other in the message.
Solution for both is the same. Accept that it doesn’t work properly and just ignore it.
For stairs it’s easy. You want to be more active by taking the stairs? Then just do that! You don’t need confirmation from your watch you just did.
And steps? You have a quite expensive sport/activity watch. So I presume you are quite active. Measure time (at least 20 minutes a day) you are active in stead of the marketing oriented 10000 steps.
