Important:
While a linked-clone pool is created, do not modify the parent virtual machine in vCenter Server. For example, do not convert the parent virtual machine to a template. The View Composer service requires that the parent virtual machine remain in a static, unaltered state during pool creation.
Please refer to VMware article as below:
https://docs.vmware.com/en/VMware-Horizon-7/7.8/horizon-console-administration/GUID-824608C8-F59D-41A2-A692-FF5CBDD683B1.html