Can't link to two different CPTs at the same time

I have 3 CPTS

1. Hospitals: Location based, with own category types and Tags
2. Doctors: Location based, with own category types and Tags
3. Doctor List: Non location based and no categories or tags

example: 1. Park Hospital Kolkata
2. Dr JP Goswami, Dr Saurav Barua, Dr XXX
3. Park Hospital Kolkata Doctor List

Doctors from No 2 are linked to 1 and 3.
Now hospital displays doctors and a link to Hospital doctor list.

But If I add Link from doctors to Tab of 3. that is doctor list, it doesnot get saved. Automatically gets removed and does not display. ( I wanted doctors list to show all doctors, while hospital only five doctors or so)

links: https://ehospital.in/hospitals/west-bengal/kolkata/park-clinic-kolkata/
https://ehospital.in/doctors_list/park-hospital-kolkata-doctors-list/
https://ehospital.in/doctors/west-bengal/kolkata/dr-saurov-baruah/