3285530 - "Your connection is not private" warning when accessing via the SAP Web Dispatcher

When trying to access the system via the SAP Web Dispatcher the following warning appears:

Another possible error code is "NET::ERR_CERT_INVALID".

In Web Dispatcher trace file, the following entries can be found related to the issue:

  SSL_get_state()==0x1180 "TLS read client certificate A"
*** ERROR in secussl_read: SSL_read() lasterr 0x20001046
  => "received a fatal TLS certificate unknown alert message from the peer"
  srv SSL session PSE "/usr/sap/<SID>/<instance name>/sec/SAPSSLS.pse" (load=<date>, rcnt=1)
    Subject : CN=<subject information> 
    Issuer  : CN=<issuer information>
    SerialNo: <serial number>
    Validity  -  NotBefore:   <Certificate validity>
                  NotAfter:   <Certificate validity>
  SSL_CTX ciphersuites=135:PFS:HIGH::EC_X25519:EC_P256:EC_HIGH
  Server SSL_CTX 7f973c0971a0 pvflags=897 (TLSv1.2,TLSv1.1,TLSv1.0,BC)
  TLSextSNI server_name="<hostname>"
  (789_REL patchno 226,linuxx86_64_gcc43) CommonCryptoLib 8.5.53 (/usr/sap/<SID>/SYS/exe/uc/linuxx86_64/libsapcrypto.so)
secussl_read: SSL_read() failed  (536875078/0x20001046)
   => "received a fatal TLS certificate unknown alert message from the peer"
  SSL NI-hdl 71: local=<local IP::<port> peer=<client IP>:<port>
<<- ERROR: SapSSLSessionStartNB(sssl_hdl=7f9730000b60)==SSSLERR_ALERT_CERTIFICATE_UNKNOWN
*** ERROR => IcmConnInitServerSSL: SapSSLSessionStartNB returned (-127): SSSLERR_ALERT_CERTIFICATE_UNKNOWN [icxxconn.c   3090]

"Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental." 

• SAP Web Dispatcher

ERR_CERT_COMMON_NAME_INVALID, insecure, SSSLERR_ALERT_CERTIFICATE_UNKNOWN, ERROR in secussl_read, SAPSSLS.pse, host mismatch, received a fatal TLS certificate unknown alert message from the peer, Your connection is not private, SSSLERR_SSL_READ, ERR_CERT_INVALID, NET::ERR_CERT_INVALID, NET::ERR_CERT_COMMON_NAME_INVALID , KBA , BC-CST-WDP , Web Dispatcher , Problem