MrZed I actually found 2 issues / bugs that cause the tutorial messages not to pop up at all even if you haven't gone through 10 sex interactions in the first stage after a bit more testing.
A thing that can cause the tutorial messages not to pop up is if you start the first stage, and quit it at any given time. Then go back into it there are no tutorial messages at all.
This explains why on first character I never saw any of the tutorial messages. Cause I launched the game. Started the first stage to see what the game looks like, beat up a few enemies then immediately quit. Exited the game and didn't bother to play the game until a few days later, which was why I didn't see any of the tutorial messages at all with my first character.
Also explains why I only saw the second tutorial message about food pick ups with my second character. Cause I went through halfway the first mission with my second character, realized I forgot equip a collar to get submission experience and restarted the mission before getting knocked down / seducing an enemy.
During the intro scene after creating a new character with QuarterMaster if you press escape instead of manually clicking through the dialogue the tutorial messages in the first stage won't pop up at all.
Which explains why on all the other test characters I created after the second one I never saw any of the tutorial messages, cause I always press escape to skip the pointless dialogue.
Also having the tutorial message only show up the first time you play during the first stage is a poor choice, because if a new player beats the entire first stage without ever having any sexual interaction they also would never see the tutorial message explaining how it works.
My suggestion would be to have the game always show the tutorial messages in the first stage until you beat it once rather than only the first time you enter it. That way if someone quits the first stage before beating it they will have at least gotten a chance to seen the tutorial messages. Have the sex tutorial messages always pop up the first 10 times a new character has a sexual interaction regardless of stage (as in remove the first stage condition), cause that would resolve the issue of a new player not seeing the sex tutorial message if they beat the first stage without ever getting into sex interaction. Add a toggleable setting that allows you to enable / disable the tutorial messages / stage ending dialogue in stages in case you want to see them again or skip them.