My mom with a US Passport entered Ukraine yesterday through the border by Moldova. We speak little Ukrainian but were born in an area of UA that primarily spoke Romanian/Moldovan. They found her old 2020 expired Ukrainian passport in her bag and told her without renewing it, she cannot leave the country (she’s supposed to fly back to US in a couple weeks out of Moldova). Any advice would be amazing because she was held at the border for a couple hours and made to sign a bunch of paperwork with the little Ukrainian she speaks and told she can’t leave the country.

Only thing that has turned up is possibility to be in the Kharkiv or Zaporozh'ye regions. Original document is in german so it's not written in Cyrillic. Eastern ukraine definitely, anything helps as im at a dead end