Welcome to the Community,
does this happen on VM reboots, or on power-cycles, i.e. after power-off - power-on?
Please check whether the VM's virtual disk has been configured as "independent nonpersitent", which will discard all changes after power off.
This happens on both VM reboots and power-cycles. How do I check the configuration of the virtual disk?
If it happens on reboots as well, then it's most likely not a VM setting.
Anyway, you may want to check the VM's virtual disk's configuration in the VM's settings.
If you are unsure, please attach the VM's configuration (.vmx) file to your next reply.