Hi Beth,
There are some limitations in web browser technology, copying and pasting text in Microsoft Office Online differs from copying and pasting text in the Office desktop applications.
You can paste a picture which you copied from Web in the document, but Word Online doesn’t support pasting pictures that are copied from other documents or programs. If there’s a picture in another document or program that you want to use in Word Online, save the picture on your computer, then go to Insert > Picture in Word Online.
Please check this article: Copy and paste in Office Online for best practice
For further checking the issue, please provide the following information:
- Which web doc are you referring here? Is it OneNote Online, Word Online etc.?
- From where have you copied the picture, internet site or other web document?
- Please save the picture in your computer and then insert the picture through Insert> Picture, as shown below.
Thanks,
Neha