Ok, I took another look at the code.
Simply put, if your relationship with her is exactly at 3, the only possibility how "Enter" doesn't trigger her relationship 4 event and the "Talk with Leyla" option is missing as well, is if you already got a (lewd) massage from her before. Which shouldn't be possible, unless you already somehow managed to triggered that event earlier than intended. But from the code surrounding the options, it doesn't seem like that should be possible... unless you did so on an older savegame from version 1.05 or earlier.
I was going to upload a new polishing update soon anyway, I'll include some minor code changes that might fix this for you.
But if you're on PC or know how to access the saves subfolder and could upload me your savegame, I'd appreciate that a lot, because I'd really like to check whether my suspicion is correct and if there's possibly some actual bug still lurking somewhere.