What update? Switcher stack was last updated 5th December 2017. There have been no other updates since that date and nobody has logged any issues about the stack with me.
Putting 1 and 1 together, it sounds like you are talking about a Stacks update, not a Switcher update? I believe an update was made for Stacks and the link for jQuery UI was broken, which someone else has discussed here already in another thread:
That looks to be what is not working in your test site. The link to jQuery UI is broken:
This is not a fault with the Switcher stack.
Perhaps you just have to change your Stacks preferences a little and continue using a CDN version of jQuery UI until a future version of Stacks fixes the jQuery UI address?
I am on annual leave this week and next week so have done no testing of the latest Stacks Beta and jQuery UI changes. And I think @isaiah has kindly said in the past that any bugs or feedback relating to Beta builds of Stacks should be posted back to his Slack group, not the forums. I’m thinking this issue you are talking about here is different to what the OP was asking for help with (stack installation).