Based on trackitt after medicals it takes anywhere from 2 to 5 months for passport request. You waited for about 4 months so I'm pretty sure you'll be getting your Request within the next month. You are almost there.
Good Luck
Status changed on Monday 20 th April and I am still waiting for PPR request. Getting kind of impatient. I thought if the online status says "Medical result have been received", PPR is on the way or has been sent already, specially if the case is with Buffalo. I haven't heard anything at all. getting a bit anxious now.