[Решено] Manually Translated Items Can't Be Marked As Complete

Background of the issue:
I am translating our website from English to German using WPML. Most translations are done by an external translator, and I am pasting them into the Translation Page. I follow a specific process using WPML's Translation Management and Translations features.

Symptoms:
After marking items as 100% translated and clicking the Complete Translation button, the items remain in the Translations queue and are not published or available on the front end via the language switcher.

Questions:
Why are manually translated items not being marked as complete in WPML?
How can I ensure that translated items are published and available on the front end?