I asked this question back in the middle of November after the episode with the archaeologist and the Sith Temple:
After having seen The Rise of SkywalkerSo have we jumped to a point in time that is past the end of TLJ?
it's now blatantly clear that not only was this after TLJ, but some distance past it, since Kylo's hunt for Sith artifacts likely only started with the broadcast mentioned in the opening crawl