Issue seems to come from Google Translate adding element to the page that NextJS does not know of.

2 solutions (more a workaround) are proposed on a shadcn issue:

• Adding translate="no" to the html tag
• Wrapping the element with a <span><span/> like so:

<Select>
  <SelectTrigger>
    <SelectValue/>
  </SelectTrigger>
  <SelectContent>
    {menuItems.map((item) => (
      <SelectItem key={item} value={item}>
        <span>{item}</span>
      </SelectItem>
    ))}
  </SelectContent>
</Select>

Thanks a lot to @Radim Vaculik for its help!