It's only an "issue" in so far as CBS have been insisting since Discovery was first announced that it (and any future TV shows) would continue to be set in the Prime universe, whereas the films (if indeed any more see the light of day after the abhorrent "Beyond" effectively killed the franchise) would be set in the Kelvin universe. They wanted a clear separation between the TV and film franchises....I also not that bothered what universe it's ment to be set
But Discovery very obviously doesn't fit in the Prime universe (or fully in the Kelvin universe for that matter it could be argued). CBS have hugely muddied the waters and I can understand why so many fans are up in arms about Discovery.
Still, they've ridden rough shod over continuity so many times in the past it's just not worth getting in a tizzy about. Just watch and enjoy I say.