after upgrde vcenter 7 , the tree view cannot see VM in second level folder

I upgraded my vCenter from 6.7 to 7.0 in my Lab , and found that the VM missing in tree view inside second level folder

sample as attached.

under DMZ , the VM can list out

in DMZ > HGC , the VM cannot list out , I cannot expand the HGC folder

but I can see all VM in right hand side

I tried to create a new folder, and I have the same result