Fixed this on the juliaup end.
So, as a bit of advertisement: if you are using juliaup on Windows (see here for an intro), then you can just get the beta channel by running juliaup add beta and it will install this beta version. To start it, you can then run julia +beta. If you already have the beta channel installed, you’ll do juliaup update beta and it will update it to this beta 3 build for you.