Turbo Golf Racing

I did this by using a console and my phone w cloud gaming, and 2 profiles. But could also be done with a friend/2nd online console.

From the Main Play menu hit to change game mode. Select Custom -> Host Game. I then changed the General setting to Private games, 8 players, any region, Bots (on or off, i had them on when i did this), bot difficulty Easy. You're welcome to select whatever 3 levels you want but I just did random levels. Allow all pickups (so you can work on the pickup achievement) then in Cores de-select any Passive Cores (blue border) you've already won with, or just keep track of what you've done.
Once done w that hit hit Host Game, this will put you back and the Main Play screen and you will be in a party of 1, hit and tab over to Friends. Invite your friend/2nd profile. From the 2nd profile accept the game invite through xbox (doesn't ask through game) you will now be in a party of 2 and can play "easy" online games wither easy bots or with just the 3 players, and they count as online games.

Now select a different Passive Core after every win (3 matches) and the cheevo should pop. I got stuck the most on forgetting which Cores I'd already used.
This method can also be used for the 5 Active Cores achievement.

Season 3's update has finally fixed this, the other Core achievement and the Dailly Missions achievement.

To unlock both core achievements you just need to win games (from your score after all 3 Holes) with different cores out of the list of available total cores. For this one you can make it easier by running passive cores in both slots so once you finish the 5 Active cores you'll only need to win 3 more games rather than another 5. I think the "Unique" identifier means that the Ball Size Changer Cores & physics changers only count 1 out of the 2, so if you win with Big Ball, you can't then get a win with Small Ball, but this would need to be confirmed.

If you get stuck at 90% and there are no issues with the Achievement service at the time, I recommend you delete your LOCAL save data, cancel the cloud save data sync when relaunching the game and trying again with the core that didn't track.

Given that the game is Early Access, there's no telling what they'll break by tweaking the game file during continued development.

Also, for this and pretty much every other grindy achievement in the game, I recommend that you use the Cloud Gaming app for Mobile/PC if you have Game Pass Ultimate and a phone & internet capable of running it, and double-box the game yourself via your primary profile streaming the game, and a dummy playing it on your Home Console. It's a very handy tool to have for games that are on game pass that don't have local multiplayer. You don't even need a 2nd controller in a lot of cases, but if you have other platforms with Bluetooth controllers (PS4/5, Switch), you can also use those with some app/program assistance to get them to show up as compatible.