Does F5 VE trail version 11.3 support device service cluster(DSC) feature?

I'd agree with nathan and suggest you break the trust and start again. However, I suspect this will be a limitation of the VE trial. Worth one more go though.

I've not thought about troubleshooting in detail too much at this point but if it helps any, these CLI commands may be more revealing as you work through the issue;

[tmsh] show cm device-group
[tmsh] run cm watch-sys-device
[tmsh] show cm device
[tmsh] run watch-devicegroup-device
[tmsh] show sys ha-status
[tmsh] show sys failover
[tmsh] show cm sync-status
[tmsh] show cm failover status
[tmsh] show cm traffic-group