How to remove drop shadow from text

Hi all, I have a bit of a newbie question that hopefully you guys can help me with.

I am writing a Qt5 PySide2 GUI application that is designed to work as a plug-in for different host applications. The problem I am having is that when I create my main window QDialog and parent it to the host applications main window my window then inherits all the styles of the host application.
I've done some searching and it looks like it's impossible to prevent a QWidget from inheriting the stylesheet of it's parent so so far my solution has been to create my own stylesheet which is more specific then the parents and set it on my main window to override the settings.

The problem I am having is that one of these host applications that I need my plug-in to run inside is applying a drop shadow to all my QLabels and QPushButtons and I'm not sure how to get rid of it. The only way I know of applying a drop shadow in Qt is to use a QGraphicsDropShadowEffect, but as far as I know these are not inherited by child widgets. The stylesheet reference page (https://doc.qt.io/qt-5/stylesheet-reference.html) makes no reference to a drop shadow style so I'm not sure how to override it to remove it.

Here are two images showing what I mean:

This image shows the correct version:
Attachment 13377

This image shows the incorrect version with what appears to be a drop shadow (that I'm not setting anywhere):
Attachment 13378

Thanks in advance