I believe this happens when the university is open - this is during the begin of Elsa route if I remember correctly (after she has blown you for the first time and you made a photo).
I have played it with the correct translation from Xorgroth translation project and was able to "unlock" Elsa just fine
Wow, thanks for your help, the Elsa conversation is fine now. I went to University and then go to business area between 18:00 to 19:00, the taxi event happened as fine.
But I got another unexpected issue. Masha's mom Irina only blow me once after 22:00 invite her to bar. Then no matter what I do, whenever I come, there is no blow work happen as walkthrough said. The depravity of Irina doesn't change after checking my Bonner outside Masha's bedroom like before. I carefully selected tell the harassment to Masha and select "I'm not sure" option before as walkthrough said. But nothing happened later. My preview save file has the same issue I don't know how to deal with it.
Anyway, there is also like Marina (Antonia's elder daughter, Dasha's elder sister) only showed in the kitchen but can't be available. Mom's wedding dress task never showed up no matter how many time I come between 20:00 to 24:00. Stepsister Yana does not progress after giving an iPhone for a blowjob. According to the walkthrough, she should come to my room to borrow a laptop to progress...
but after all, the Irina issue is the most annoying one
. I can see Irina sometime in Antonia's house but no further progress ever happened later. So confusing about the trigger status.