Stable Union / Uniao Estavel - Proof of single status required?

For those of you who have recently obtained residency based on a Stable Union, were you required to have a document from your home country confirming your single status? If so, who requested to see it?

It's not on the PF list of requirements and the Cartorio doesn't need one but I've seen some people mentioning it.

I'm happy to sign a declaration in Brazil confirming my single status but it is a real pain to get such a document from my home country so I'd prefer to avoid that step if at all possible but want to be prepared.

Thank you!

Yes it was a requirement for  a divorce decree for me at the cartorio  and (translated) as will as at the PF for RNE. (Was before the 2017 laws)

thank you Texanbrazil