Are you using the Gutenberg Blocks or the legacy TinyMCE/WYSIWYG Editor?
Also, could you check your website, on the front end, where you would expect the image, and see the console of the browser, if it shows any JS errors?
While in there, also check if the HTML source is present for the Image (in the browser console “Elements” tab, look for the img
HTML tag)
If you use the Gutenberg Blocks, to add images, it would be helpful to know what block you use. In case you use the TinyMCE Editor, it would be good to check what you see in the editor when switching to the “Text” Edit mode, in order to know if the HTML somehow is corrupted.
Finally, if you where to insert a simple HTML code like the below, either in a HTML Block or in Text Mode if you use the TinyMCE Editor, can you see the image?
<img src="https://www.w3schools.com/tags/img_girl.jpg" alt="image" width="500" height="600">
Let me know the results.