I did it while doing Kovit's route, after the s*x scenes with him in the hospital I returned the next day and talked to John a couple of times. I have problem with the green haired doctor, Dr Ken
Viewing post in Version 1.14 and Future Update Schedule comments
Unfortunately it was on the first build of the game but yes, I focused only on Kovit. I tried it now on the the 1.14 build and it works for me, I also remember talking to him at every occasion I got since the hospital became available because I was curious of what he was going to tell me, maybe it was that! Did you perhaps unlocked Dr. Ken?