not working for me!

Try the following:

li#wp-admin-bar-abus_switch_to_user.menupop {
  position: relative;
}
.ab-sub-wrapper {
  position: relative;
  z-index: 99;
}

Thanks…I’ve already tried .ab-sub-wrapper – as I said z-index has no effect.
Problem is wp-admin-bar has a z-index of 999999.
Now trying to move wp account bar which control the name message down using:
li#wp-admin-bar-my-account, a.ab-item{
z-index:-999 !important;
}
But this also has no effect.

The CSS I posted above worked for me on my install, therefore must be something else going on.

I would think the z-index on the admin bar is not an affect as the elements in question are within that and relative to each other.

Made some progress…found that #wpadminbar ul li has a z-index of 99999.
If I apply

li#wp-admin-bar-my-account, a.ab-item, .menupop with-avatar{
		z-index:-999 !important;
	}

I can’t seem to override the z-index of #wpadminbar ul li, but if I remove it in my browser inspect mode it works.

Any idea of the stacking order? What am I doing wrong?

Got it!

it was the relative positioning on the wp user link.

Changed it to:

#wp-admin-bar-top-secondary{/*controls wp user link*/
		position: absolute;
		z-index:-999 !important
	}

Combined with:

#abus_search_text{
	background-color: #fff;
	color: #000;
	font-weight: bold;
	z-index:1 !important;
}

Fixes both issues!
Thanks for your help.