WSUS Certificat

Hi 

We have installed a PM server Windows 2k16

We have an WSUS for SCCM 

We have an SCCM Primary site server 

We use the SSL port 8531 for WSUS and SCCM DP

First TEST : deploy sefsigned certificat : ERROR

Second TEST : import IIS Certificat (certificat used by WSUS ): 

Publishing error : Signed file 

When we want to creat a new certificat : PB with sccm DP 

Question what is the good recommandation:

Seft signed certificat 

Its is possible to use the 8530 port (HTTP) whith the existing WSUS (SCCM)

Thanks for your help