Hello, I'm Marcos Independent Advisor, and can help you with your request
Check If you're following right process through this Link:
https://support.office.com/en-us/article/save-p...;
And you can try to handle follow these steps:
TURNING OFF AUTOMATIC PICTURE COMPRESSION IN POWERPOINT 2013 & 2016:
Click "FILE / OPTIONS / ADVANCED".
In the list at IMAGE SIZE AND QUALITY, do one of the following:
Ignore the list to select your current document by default.
Click the list arrow and select the file that you want to turn off picture compression for.
Choose All New Documents to turn off picture compression on all future documents.
Under IMAGE SIZE AND QUALITY, select the DO NOT COMPRESS IMAGES IN FILE check box. This setting applies to only the document that you selected in the Image Size and Quality list, unless you selected All New Documents.
NOW, LET'S TACKLE THE ACROBAT SETTINGS THAT NEED TO BE FIXED
Open PowerPoint or Word.
Click on the "Acrobat" menu.
Click on the "Preferences" menu.
Click on the "Advanced Settings ..." button.
Click on the "Images" item.
Select "Off" for "Downsample" in the "Color Images", "Greyscale Images", and "Monochrome Images" sections.
Select "Off" or "ZIP" for "Compression" in the "Color Images", "Greyscale Images", and "Monochrome Images" sections.
Click "OK"
Click "OK"
Let me know If it works.