How to change text within a tag in a scanned document

I have a example scanned document that I'm trying to make accessible. I can fix all the normal issues relating to accessibility however, Acrobat seems to create broken text within the tags which is read by a screen reader in testing. I'm assuming this is down to the font used which is confusing acrobat. I've tried right clicking on the tag, clicking properties and entering the correct text in the "Actual text" input but the end result is the same - the broken text is what is read by a screen reader. I know I could edit the text like any normal text but I don't have that font installed.

Is there no way to change the text within the tag without visually changing the text for the purposes of what a screen reader will read?

See attached screenshot for broken text in text VS visual text.

Thanks in advance!