I am currently into modern soul, R&B and jazzy stuff like Hiatus Kaiyote, Thundercat, and Moses Sumney. I am looking for similar artists/records like them. Any suggestions?
They're all fairly unique artists, and unfortunately, I'm not familiar enough with each to make recommendations. You might see how YouTube's, Spotify's and Amazon's various algorithms compare on listening suggestions.
In terms of historical stuff, Thundercat grew up listening to a lot of different stuff – his dad is a fairly accomplished drummer with jazz and Motown credits. Thundercat also cites Jaco, Stanley Clarke and Marcus Miller as his three biggest bass influences, so there's tons of listening material there.
Lastly, IMHO, present-day R&B and soul artists owe a huge debt of gratitude to Solomon Burke (1940-2010) for paving the way. You might check out some of Burke's impressive catalog. The Best of Solomon Burke (Atlantic, 1965) is a good place to start.