Background of the issue:
I am experiencing issues when switching from Polylang to WPML on my site hidden link. I have created a Loom video to demonstrate the issue: hidden link.
Thank you for contacting WPML support. While you are waiting for one of my colleagues to take this ticket and work on it, let me provide you with first debugging steps or if I can perhaps help with the issue quickly.
Media Translation
Your images are organized by language inside WPML, that's why you have to switch the language inside the library. If you wish to connect the images, informing WPML which is the German version of an English image or vice versa, you have to go to WPML > Media Translation and click on the plus sign of an image. There, you can inform WPML which image should be used in another language, when the content contains the original image. This needs to be done in Media Translation and not in the media library.
About the duplication of content. It looks like there's some conflict between WPML and the plugin you're using. I'd recommend you to try with another plugin. The plugin below is compatible with WPML. Please give it a try and let us know: https://wpml.org/plugin/duplicate-page/
In case it also doesn't work, it's worth investigating the critical error that happens upon duplication. Please share the error log with us, in case it doesn't work with the plugin I suggested.
Elementor
WPML offers you two ways of translating content: WPML's Translation Editor or the WP Editor. The first option is more practical when the pages have the same content, only translated. The latter works best if you wish to have different settings, layout, or content between languages. It's essential that they do not get mixed, meaning that when using WPML's translation editor, translations should not be edited directly with the page editor, as it can lead to problems like the one you're having.
In your case, if you wish to keep using WPML's translation editor, and you wish to keep the pages as exact copies in terms of layout and settings, I'd recommend you to delete the problematic translation and recreate it with WPML's Translation Editor. To delete a translation go to the pages tab, switch the language in the top-bar, send the page to the trash and completely remove it from the trash.
As a general side-note, it's not recommended to have both WPML and Polylang (or any other translation plugin) active at the same time. When testing, please leave only one plugin activated.
If that does not help, one of my colleagues will soon come to continue support. It's likely that this ticket will need to be split into other, as we usually address one issue per ticket.
