Unusable AI Masking in Resolve Studio 20 Beta

I have a MacBook Air 2024 with an M3 and 16 GB of memory running Sequoia 15.3.2.

I was trying to do a very simple two node transformation in Color with a source node and a second defocus node.

I'm trying to defocus the background.

When I tried this, tracking never exceeded 1 fps and sometimes dropped to zero.

NOTHING ELSE was running on the Mac at the time.

Resolve Studio 19 has no problems with this.

My understanding is that this computer should be adequate to the task.

Note that I may have submitted this at least one other time and perhaps a second because I didn't see it come up and I was confused it was accepted. My apologies.

Here's the missing information:

DaVinci Studio 20.0B Build 38.

The .spx file can be found here ((embedded spaces!):

https://www .dropbox .com/scl/fi/726d6zcks82n1vf884bfs/MacBook-Air.spx?rlkey=evwoz7xabq01xhcrlwyztoiw5&st=eam7ot2w&dl=0

Color tab being used to do masking:

https://www .dropbox .com/scl/fi/k293gdt3tg1itf0ivtpy2/Screenshot-2025-05-14-at-1.16.30-PM.png?rlkey=taxpbmi7l5zw42ohrurox0oih&st=wg9zd0y3&dl=0

Edit tab showing clip length

https://www .dropbox .com/scl/fi/hazh28qrd7yht3xsaoglr/Screenshot-2025-05-14-at-1.17.42-PM.png?rlkey=ya0y7tznygnphrn1rzhn3jmbz&st=a2vn0duj&dl=0