Okay so I did a few testings, the results are... well interesting.
First I created a vampire and a normal Sim. They weren't even friends yet but my mortal Sim had the Ask to Turn option; my vampire Sim didn't have the Offer to Turn interaction though.
Then I visited a family of two, a young adult vampire and his elderly mortal father. The son has the ability to turn others yet it was not there this time when I clearly remember it being there before the newest update. (He didn't even have that ability back then - before the update - but the option was there anyway)
I guess it was taken out since vampire masters and their offsprings are kind of count as family members (this explains why the Domestic trait works between a vampire and a Sim they turned) and it would mess the family tree up? Not sure.
Moving on I visited an already existing family of a vampire and a normal Sim whom were BFFs. No option from either of them.
For the fourth time I created another vampire and a mortal Sim, made them interact until they were Good Friends, leveled my vampire Sim until she could purchase the Vampire Creation ability then checked if the option was there - it was not.
However a bit later they interacted again and as soon as the conversation reached "Pleasant Conversation", my mortal Sim finally had the option to Ask to Turn just like my vampire the Offer to Turn one.
Is this something new then? Because if it is, it seems it's much harder to turn someone which I really like.
But if not... Maybe it's just a weird glitch?
I was having the same problem. The "pleasant conversation" solution worked to bring back the "offer to turn" and "ask to turn" options. However, after the vampire bit the sim the interaction would end and the sim would not be turned. This was being caused by the fame quirk "no touching". After the vampire had raised their relationship with the sim the interaction completed and the sim was turned
