Bottom part of the print is being left out

[dpanse]

The bottom part of my print seems to be left out and the printer starts printing a few millimeters above the base.
IMG_3336.jpg

IMG_3337.jpg

It seems to have left out all the part marked below:
Screen Shot 2022-02-10 at 4.46.30 PM.jpg
Im using an Creality Ender 3 Pro. Printing using Ultimaker.
Any idea what could be going wrong?
Im got the STL from https://www.thingiverse.com/thing:3780786

Thank you.

[dpanse]

Is anyone able to help here? Thanks.