[مغلق] Page translations are not saved

Background of the issue:
The primary language of the website is German. I am trying to translate the pages into Russian. The translation editor opens correctly, and I translate all the necessary fields and save them. Articles and strings are translated and saved successfully. The issue only occurs with the translations of pages. I have tried disabling all plugins one by one, but the problem persists. All plugins are up to date.

Symptoms:
A pencil icon appears next to the page in the list for a short time and then disappears. The translated page in Russian does not appear. When I go back to the translation editor, all fields show as 100% translated.

Questions:
Why are the page translations not being saved?
Why does the pencil icon disappear after a short time?
Why does the translated page in Russian not appear despite showing 100% translated in the editor?