2.18 regression: sl-select does not show selected values on first render

[shonya3]

Describe the bug

Select element does not show selected values on first render since 3.18.

Demo

I'll link two stackblitz demo. 2.17.1 - wihtout bug, and 2.18 - with bug(does not show values).

2.17.1 (values rendered) https://stackblitz.com/edit/vitejs-vite-q2mcgs?file=package.json,src%2Fhome-page.ts

2.18 (no values) https://stackblitz.com/edit/vitejs-vite-y9ciev?file=src%2Fhome-page.ts&terminal=dev
But if you await promise and request update, then values get rendered.
Uncomment this in 3.18 example in home-page.ts :

 // protected async firstUpdated() {
  //   await new Promise((r) => setTimeout(r));
  //   this.requestUpdate();
  // }

Screenshots

3.17.1

3.18

Browser / OS

• OS: Windows 11
• Browser: Chrome
• Browser version: 130

[KonnorRogers]

Duplicate of #1570 (comment)

(going to leave this bug open since I never made a formal report)

Thanks, for the report, I'm looking into it. The TLDR is that the value property is being triggered before the element connects and Lit's lifecycle has started so it never toggles the valueHasChanged property.