I am trying to: use a cred form to upload an image
Link to a page where the issue can be seen: hidden link
I expected to see: the image I uploaded
Instead, I got: broken link due to wrong image path
Check this out hidden link
If you login you have a "Modify" button where you can upload the image.
Until my last plugin update the image was uploaded to the wp-upload files.
Now, it gets no path and is looking for the image in a wrong path
Your maps page is not loading correctly because of a JS error from another plugin (um-messaging), you need to fix that error or de-activate the plugin.
Regarding the image URL issue, I've tested and can see the issue on your site, but I've been unable to reproduce it on a local test site.
I set that up with WP 4.9 to check if that were the culprit, but it seems not.
So I'd need to rule out conflicts on your own site to see if there is something else interfering with the process. I can see that the image gets uploaded to the media library correctly, but the value stored for the field stores only the image filename and not the full path.
Do you have a staging site for testing on? (If not, you really should! Speak to your host.)
Could you please disable all non-Toolset plugins and switch theme to twentynineteen then try again. If the issue disappears then it should be possible to determine the source of any conflict by a process of elimination. From the description of your image field I'm guessing you may some custom validation code, but I can't see where that is added.
Let me know how that goes so I can see how to proceed.