Unable to display Images

I'm fairly new to Power BI and have been trundling along just fine until now. I'm after soem help with what I think is probably a simple fix...

I'm trying to get a simple table to return an image when the appropriate selection is made in the slicer. Essentially I have a small table (produced using MS Excel) comprising of two columns. Column A contains the name of a number of company departments, Column B contains the image URL of the org strtcture for that department. However depsite trying many things over many hours I can't get it to return a thing even though the filter is working okay.

So far I have tried:

• Alternative image hosting: ImgBB, One Drive, even using google images with known good urls
• Alternative image format: jpg, png, even Base64 (Base64 was the most promising as it displayed around 10% of the image - however I dont think the cell could hold enough characters so only part of the image was displayed)
• Ensuring the column is formatted correctly in Power BI (formatted as Image URL)
• Alternative image visualisation tools

The net effect being that nothing works. All I'm getting in all cases except Base64 is a standard image icon appearing where the image should be. I'm beginning to think that there's some kind of blocking of external URLs within Power BI stopping all external references from returning.

Any thoughts?