Welcome to the WPML support forum. I will do my best to help you to resolve the issue.
Please allow me to make a duplicator copy of your site using the Duplicator plugin(https://wordpress.org/plugins/duplicator/) for debugging the issue on my local server. So we can troubleshoot the issue without affecting your live site.
I seemed to have fixed this issue by deleting those images. They were not WPML related. But the other PHP warnings are still there:
[15-Oct-2022 15:19:49 UTC] PHP Warning: Undefined array key "15-cm" in /home/mymoissanite/public_html/staging/wp-content/plugins/woocommerce/src/Internal/ProductAttributesLookup/LookupDataStore.php on line 459
[15-Oct-2022 15:19:49 UTC] PHP Warning: Undefined array key "16-5-cm" in /home/mymoissanite/public_html/staging/wp-content/plugins/woocommerce/src/Internal/ProductAttributesLookup/LookupDataStore.php on line 459
[15-Oct-2022 15:19:49 UTC] PHP Warning: Undefined array key "18-cm" in /home/mymoissanite/public_html/staging/wp-content/plugins/woocommerce/src/Internal/ProductAttributesLookup/LookupDataStore.php on line 459
[15-Oct-2022 15:19:49 UTC] PHP Warning: Undefined array key "19-cm" in /home/mymoissanite/public_html/staging/wp-content/plugins/woocommerce/src/Internal/ProductAttributesLookup/LookupDataStore.php on line 459
[15-Oct-2022 15:19:49 UTC] PHP Warning: Undefined array key "20-cm" in /home/mymoissanite/public_html/staging/wp-content/plugins/woocommerce/src/Internal/ProductAttributesLookup/LookupDataStore.php on line 459
[15-Oct-2022 15:19:49 UTC] PHP Warning: Undefined array key "21-5-cm" in /home/mymoissanite/public_html/staging/wp-content/plugins/woocommerce/src/Internal/ProductAttributesLookup/LookupDataStore.php on line 459
These are WPML related because they have to do with product attribute (lengte) translations.
This ticket is now closed. If you're a WPML client and need related help, please open a new support ticket.