I'm hoping someone can help me figure out what settings I need enabled to have historical draft classes populate correctly.

I have one league that I started in 2008 with the Nationals. The draft in this league is working as I like. Players are available in the draft the off-season before they made their Minor League debut. So the first draft in this league was December 2008, and it included Trout, Arenado, J.D. Martinez, Shelby Miller, Mike Minor, all guys who were drafted and made their MILB debuts in 2009. Strasburg, who was drafted in 2009 but made his MILB debut in 2010, was available in the next draft, after the 2009 season. Same story for Harper, he was available the draft after the 2010 season. These drafts are populated with thousands of prospects. Prospects who made their MILB debuts in 2008 or earlier, such as Freddie Freeman and Buster Posey, were already in the game and on their correct teams when I created the league.

Now, I want to make a new league starting in 2018. I checked the Import Negro Leagues and Minor leagues option, as well as automatically import historical rookies. But these drafts are not being populated the way they are in my other historical league. The 2018 draft has a total of 26 players. The top players in the draft are Bo Bichette and Cavan Biggio, guys drafted IRL in 2016 who should already be in the Blue Jays minors when I start the league if it was working like my other league did. Even more confusing, guys drafted in 2016 or even 2017 and 2018 IRL do already exist on the correct teams; guys like Casey Mize, Royce Lewis, Kyle Wright, Pete Alonso, and Bryan Reynolds. I'm really not sure why it's treating some guys, like Bichette and Biggio, differently than the others.

What gives? What settings do I need to have checked on league creation to make sure it works like it did for my 2008 league? I thought I checked the same options, and have tried multiple times with different options checked to set up the 2018 one correctly, but no luck thus far.