Hreflang implementation issue

[Starcom_Search]

We are currently handling search for a global brand www.example.com which has presence in many countries worldwide. To help Google understand that there is an alternate version of the website available in another language, we have used “hreflang” tags. Also, there is a mother website (www.example.com/global) which is given the attribution of “x-default” in the “hreflang” tag. For Malaysia as a geolocation, the mother website is ranking instead of the local website (www.example.com/my) for majority of the products.

The code used for “hreflang” tag execution, on a product page, being:

These “hreflang” tags are also present in the XML sitemap of the website, mentioning them below:

<loc>http://www.example.com/my/product_name</loc>

<lastmod>2017-06-20</lastmod>

Is this implementation of “hreflang” tags fine? As this implementation is true across all geo-locations, but the mother website is out-ranking me only in the Malaysia market.

If the implementation is correct, what could be other reasons for the same ranking issue, as all other SEO elements have been thoroughly verified and they seem fine.