Since the created Enclave is an independent Enclave if the service class is not provided when it is created it will inherit the creating address spaces service class.
For example, if you start SYSVIEW via TSO and your service class was originally NPTSO, then the enclave created by SYSVIEW will be NPTSO.
If you change your TSO session to SYSSTC, via SYSVIEW, it will not change the enclave service class until you bounce your SYSVIEW session so you would see your TSDBD in ACTIVITY as SYSSTC but your enclave would still be NPTSO.
There are a few ways you can control it.
1. Set SYSVUSER to SYSSTC via OPTIONS parm WLM-Service-Class. Based on the capture you sent in I can see it is set to INTERFACE=MAIN, so removing the IF and ENDIF would allow all interfaces to be set to SYSSTC. Then when using the VTAM interface you would always insure the enclave would be set to SYSSTC.
2. Have your TSO session set SYSSTC via WLM every time you logon, that way when you start your SYSVIEW session it should inherit SYSSTC from your TSO session.
3. Set your TSO session to SYSSTC via ACTIVITY display, then exit and reenter SYSVIEW.
4. Set yourself manually to SYSSTC on ACTIVITY then on WMENCLAV.