I recently came across an issue where the vRealize Life Cycle Manager 2.1 has the Deploy option greyed out in SDDC Manager in VCF 3.10.x and the issue looks like the screenshot below:

The issue happened as we were using VLAN Backed Network for vRealize products instead of AVN in this version of VCF

The solution is as follows:

Log in to SDDC Manager by using a secure shell (SSH) client, use the account vcf to login into SSH session
Type su to elevate to root and enter the root_password.
Enter the following and press enter.

cd /home/vcf
echo "feature.vrealize.enable.non.avn.deployments=true" >> feature.properties
chown vcf:vcf feature.properties
chmod 644 feature.properties
/opt/vmware/vcf/operationsmanager/scripts/cli/sddcmanager_restart_services.sh

When prompted enter Y to confirm.​​​​​​​ vRealize Suite deployments using SDDC Manager will now be deployed to VLAN backed networks

This is taken from the VMware KB Article https://kb.vmware.com/s/article/79267

Hope this helps if you are using VLAN Backed Network for vRealize Components when deploying a new VCF 3.10.x version in your environment.