Despite, however

"While dark energy makes up about 74% of the Universe, dark matter - which does not reflect or emit detectable light - accounts for 22%. Ordinary matter - gas, stars, planets and galaxies - makes up just 4% of the cosmos.

However, despite scientists being able to infer the existence of dark energy and dark matter, these phenomena still elude a full explanation." (From the BBC web site.)

Hi,

Is the preposition 'despite' a subordinating conjunction, here, joining the main clause 'these phenomena still elude a full explanation' with non-finite clause 'scientists being able to infer the existence of dark energy and dark matter'?

Does the adverb 'however', here, express a degree, contrast or is it a mere discourse marker that lost his adverbial function?

Thank you.