Recently, IONOS and Nextcloud announced their new, sovereign office suite called “Euro-Office” and claimed they were using components of ONLYOFFICE. It seems they are doing so without checking the licences first and without cooperating with them.
Original announcement:
Nextcloud and Ionos are promising a modern, open-source office suite for the summer. To achieve this goal, they have forked OnlyOffice.
heise.de
ONLYOFFICE reply:
Based on publicly available information, the “Euro-Office” project uses technology derived from ONLYOFFICE editors in violation of our licensing terms and of international intellectual property law.
onlyoffice.com
Their license also says they will not let anyone use their logo. So it doesn't appear to be a reasonable attribution.