WordPress 6.7 has introduced a new issue that impact translations, please update WooCommerce and WPML to the latest versions before you report issues. More about this here - https://wpml.org/errata/php-error-wp-6-7-notice-function-_load_textdomain_just_in_time-was-called/
2) Not working as it works in Gen2. If you paste a word on top of a marked word, the marker is removed (unless you do not select the whole marked word, but part of it).
3) Random behaviour: Sometimes it does not copy the markers and when selecting a marker all the others are added automatically. However, once the segment is saved and then reopened the markers are gone. Other times it seems to work okay
I have tested this on a sandbox provided for your colleague, as well as our site