i don't know about patch update but i did sex with them.
well i dont know exactly what was the problem for that but here a few tips that i get after playing like 4-5 times already. U need to earn a point ( intelligent, strenght, lust) in order to have sex according to what charac u have high relay point. Higher lust point will lead you to sex scene for some certain character and unlock their sex scene, that also apply with strenght point and intelligent. But overall it depend 100% on ur choice. For me i do have a lot of intelligent point and high relay point with rachel that lead to sex. If u dont have high intelligent point for rachel u cant possibly had sex with her. Some of choice will add either lust+relay or lust + intel or just intel or lust depend on ur choice. So choose carefully. There are some sex scene that require strenght with ashley ( but i havent try it yet ). hopefully this will help you to figure out what u missing :)
i havent play this latest version but will do later, if i remember correctly i got 20 point of intelligent and 32 relay point for rachel. For ashely u need strenght and lust + relay point only, even if u lack of strenght u still can have sex with her but the extra scene will be lock. U can gain point on the choice u made. For example when u first meet ashley there will be an option where u need to choose wether " to look back ( Lust + relay point for ashley) " or " dont waste any time ( +1 Intelligent ) ". Basically for ashely u just need to always be positive and show affection to her. To gain intelligent u need to be smart and be able to hold ur lust for some certain choice and event. for other character i dont know how because they still dont have any scene yet. Maybe in future update they will. Oh btw u can gain a lot of intel point with rachel event.