It’s a lot easier if I post the link to a test app
Test Dropdown App
I set every placeholder text change to “It works”, so if it doesn’t change to that when the placeholder is changed, then it doesn’t work.
Changing 3 properties on Focus:
Placeholder, Font Size, and Placeholder Color
Font-size and placeholder color works
Placeholder doesn’t on both firefox and chrome
Changing 3 properties on Hover
Placeholder, Font Size, and Placeholder Color
Works as expected
Changing 2 properties on Hover
Placeholder and Placeholder Color
Firefox: Only change color
Chrome: Works as expected
From what’s happening, I bet there are more permutations(if time permitted to suss them out) that cause the functionality to fail, like trying with safari or changing other properties.