This is based only on translating the message, so I might be wrong, but:
The message Flow-rev-message-edit-post-recentchanges-summary says "{{GENDER:$2|Edited}} a post". I suspect that this appears after a username. This may work in English, where the username happens to be in the beginning of the sentence, but in other languages it's not necessarily in the beginning.
The username should be explicitly in the message. Otherwise it's "lego" ( https://www.mediawiki.org/wiki/Localisation#Avoid_patchwork_messages ).

Thanks!

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