You’re correct. It does stick to the PDMS layer when printing. And you’ll keep getting these warped parts if you don’t support the ‘floating’ parts with actual supports. Add supports and print it again. Then let it cure under the sunlight, or in a uv curing chamber and you’ll notice the part will stay straight. Don’t over-wash it in IPA though, that could cause it to warp too.
I don’t know how much experience you have with SLA printers, but it seems you’re using it as an upside down FDM printer. Nearly every model in an SLA printer needs supports to print correctly (see the 3rd button in Preform).
One other thing I noticed in your video: If you keep printing cylinders this way, they will most probably always (and I do mean always) fail! The bottom of your cyilinders are closed off. This means that every time the printer is printing a layer and connecting to the PDMS layer, you’re creating a ‘vacuum’ inside the model. This will create a blow-out sooner or later uring the print, and it seems it did at the end of your print as seen in the video. You’ll have a blob on your PDMS layer as well!
So either, create a drain whole, or flip the cyilinder so the opening is facing the build platform and use suoports!
/Here’s a simple quick guide I wrote a while ago to help you get going:
Good luck!