Why my Gear S3 is not pairing with Samsung Gear app in a Moto G phone?

[AC Question]

i have a Moto G 2nd gen phone Android 6.0, downloaded samsung gear app but I cant find and pair my Gear S3. Tested with Nexus 4 and not working as well. I did the same procedure with iOS and Samsung S6 and it works. Seems that it is a compatibility issue.
Anyone with same issue? Are there a workaround.
My gear S3 standalone only lacks a lot of features.....