When Form 1 prints, does build platform contact with PDMS layer?
It looks like contact each other when I print.
Is it normal?
Yes, until the raft starts to show up. Then the part will hover at the Z height setting above it. i.e. .1mm above with resin between the model and the PDMS layer.
… It is normal as long as your prints are coming out correctly. If not, I would open a support ticket.