This is one of those cases where there are two hostas with the same name. One is registered and, therefore, the "official" version of H. 'Oasis' while the other is a non-registered plant and needs to be renamed to avoid further confusion.

This seedling selection of unidentified parentage was registered by Dick and Jane Ward of Ohio in 2012. It is a large size plant about 22 inches high by 36 inches wide with intensely blue-green foliage. The leaves are nearly round, flat and dull on top. Near white flowers bloom from late June into July.

According to The Hostapedia by Mark Zilis (2009), "...displays H. 'Sieboldiana'-type traits."

Hosta Helper will call this plant 'Oasis' (Ward) 

This seedling of H. 'Aspen Blue' was originated by Alex Malloy of New York. It is a medium size hosta with gold colored foliage. The name will need to be changed.

Hosta Helper will call this plant 'Oasis' (Malloy)