Hi @Mike van Treek-Nilsson,
Thank you for reaching out to Microsoft Q&A Forum.
JPG files do not natively support transparency. As a result, the image may have been subject to legacy rendering behaviors such as simulated white backgrounds, shape‑based clipping, reliance on legacy z‑order and bounding box calculations or flattening of the image and text layers during export.
PowerPoint for the web uses a unified SVG‑ and canvas‑based rendering engine. With this approach, JPG images that previously appeared to have solid white backgrounds may now be treated as having a transparent canvas or an altered bounding box. As a result, text boxes positioned beneath or aligned to the image can appear offset, and object layering (z‑order) may be recalculated differently.
LibreOffice, by contrast, uses its own traditional layout engine, preserves the original bounding‑box calculations, and does not depend on browser‑based SVG rendering. As a result, it renders the file as originally designed, effectively acting as a reference point that confirms the file itself is not corrupted.
As a workaround, you can try convert your JPG images into PNG:
- Open the slide in desktop PowerPoint
- Right‑click the image and select Save as Picture
- Save the image as PNG
- Reinsert the PNG into the slide
- Re‑upload the file to OneDrive and open it in PowerPoint for the web
Using a PNG format improves rendering consistency because transparency is handled explicitly rather than inferred, which helps maintain accurate bounding‑box calculations while fully preserving image quality.
If the slide is not intended to be edited in PowerPoint for the web, you can flatten the content to maintain consistent rendering. Select the image and text together, copy them, then use Paste Special → Picture and save the file.
Additionally, I believe this is an important issue that you can notify to the Microsoft development team to fix on behalf of many users, and your feedback can help prioritize it. Please share your feedback directly with the PowerPoint team through the Feedback Hub by submitting your feedback directly to PowerPoint · Community, where Microsoft product development team can know your requirements and ideas for product improvements. The team actively monitors user input, and many improvements have been made based on community suggestions.

Note: As Microsoft Community moderators, please note that we are not involved in product design decisions and do not have direct access to the development roadmap, we want to assure you that your feedback has been acknowledged and is valued.
In the meantime, if you see my replies bring helpful information, please kindly accept it as an answer and vote it up by your original account, which raised this question. Once marked, it will automatically pin to top. As other users will also search information in this community, your valuable vote up will definitely also help other users who have similar queries easily to find the correct channel and useful information more quickly.
I hope this provides enough clarity and helps you stay inform with your current situation.
Thank you for your patience and your understanding. If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you.
Note: Follow the steps in our documentation to enable email notifications if you want to receive email notifications related to this topic.