Magento – All upsells products are not showing on product view/details page

I am facing strange issue with usells products selected for a product.
I have selected 11 products as upsells out of one is disabled so total 10 products as in screen shot

but in product view page it showing only 6 products.

I have tried following things to correct it

1 ) Ensure all products are set to enabled

2 ) Check that the products are set to In Stock or that they have manage stock set to "no"

3 ) Ensure products are set to visibility of "Catalog, Search"

4 ) Check that products are assigned to active categories

5 ) If on a multi store setup ensure that products are available on the store view you are reviewing

6 ) Go to System>Index Management select all re-index (you could reindex individually but reindexing it all won't hurt)

7 ) If you are running a 3rd party cache flush these as well. (note: most full page caches will not cache catalog/product pages)

Note: My application has 3 website and two store views, so I checked the website tab also

website tab screenshot:

Can anyone faced this kind of issue before. ?