Good day to you Barry_a_s,
It would be helpful if you could let us know what type of image you’re seeing. Is it an image from the website itself, a general attachment image or something different? In both scenarios, typing and pasting, does tapping the link take you to the same place?
Your profile shows we’re working with an iPad (5th generation). Is it running the latest iPadOS version available? You can verify in Settings > General > Software Update. If not, please install any available updates after making a backup.
Also, just to be sure the behavior is the same, are you cutting or copying from the Safari URL bar? Might there be any other common situations when this happens such as, in a fowarded email, always to one specific contact or email service provider, if you have multiple email accounts set up does it happen when sending from a specific account? Anything we can use to isolate the situation could be useful.
It almost sounds like the Mail app may be showing a preview of the link in the Mail app. When you paste the link, do you see a small down arrow at the end of the link that if you tap it says “Show Link Preview” or if a link shows a preview and you tap the preview, does an small down arrow appear on the right hand side of the preview where you can tap it and have the option to open the link or convert to a plain link?
Thanks.