OnlyOffice fails to sync with Nextcloud

i did this

rm /etc/dnsmasq.d/office.DOMAIN.TLD
systemctl restart dnsmasq

in an attempt to help myself by following this thread, but the only thing i achieved is being able to run the examples page (the original sync error still exist).

actually, when i try to create/edit a file in the example page the files wouldn’t even load so i guess it’s an extra proof the integration is not working if we needed one more.