Opening a HTML file in Word 2016/2019 ignores image size

I have the following problem: trying to open a .html file in Word containing some paragraphs and an image stored as base64 in Word.

<html>
<p> Sample text </p><p><img alt="ss" width='50' height='50' src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAASwAAAHCCAYAAABVM/SHAAAABHNC[...]Jggg=="/></p><p> </p></html>

On some of my company machines this works and the image is shown in the size specified in the IMG tag. On other machines the image always opens in its max size, ignoring the size attributes.

Has anyone dealt with this issue and can point me in the direction of what is causing this difference? We thought originally that it is connected to Office 365 vs Desktop installation but the same issue happens on another hybrid 365/desktop installation of Word.

We also literally checked ALL the settings in Word and all the active COM Add-ins. no differences there between working/not working machines.

The problem is not only when viewing - we have an app written which saves Word documents from HTML files and this is messing up the layout o fthose files on some machines.

Many thanks in advance for any suggestions!