When trying to open an exported mind map I get message “This file is corrupt. Try to repair”. Repair is working (inside of Word) but this is annoying and does not give a feeling of trust.
What format are you exporting? What software did you use to open it?
I exported my mind map to “MS Word (docx)” via the share mindmap menu. I used latest word version on Mac (o365 subscription), which is 16.43 (20110804).