UIA Mode Element issue after invoking JavaScript with Web Application

[DhivyaMani]

I am using Blue Prism (v.6.7.3) to interact with a web application using Edge browser (Version 121.0.2277.128 (Official build) (64-bit)).
I have tried to use AA mode, but I was facing issues with accessibility, and unable to highlight spied elements.So I ended up using UIA mode, as browser mode is also not supported by our current version of BP.

I am trying to fill a form with 5-6 fields which are textboxes, and are identical in every aspect.
I don't want to use match index as the only unique identifier as the form may undergo changes in future.
There is no other unique identifiers like UIA Name, UIA Automation ID, Class Name etc.

I checked in the HTML of the website, it has certain attributes which have unique names for our fields, but those were not being captured by Blue Prism.
I have then used a JavaScript (invoked using a Bookmarklet click) to modify the "placeholder" attribute.
I will always invoke this JS before interacting with the elements.
This "placeholder" is now recognised by Blue Prism as UIA name, and I am able to spy the elements.
But the issue is, I am not able to highlight them in the first attempt. 
They are only highlighted once Blue Prism interacted with the element either by Focusing or by Clicking it.

Has anyone else faced these kind of issues before?
Any suggestions from the community are welcome

[harish.m]

Hi Dhivya Mani,

The issue you encountered is based on the application. I have faced  multiple instance .

In general Highlight to the element is used for verification purpose. I would follow  this approach when I faced similar issue

First make sure the Application is maximized and activated and the next step is focus the  element if I'm working on browser mode
Also I would also suggest  try UIA mode and see the application behavior