When editing a category the parent category reverts back to top level category.
When editing a currency all fields are emtpy.
This might have something to do with the database problem reported here https://forum.virtuemart.net/index.php?topic=150047.msg536124#msg536124 (https://forum.virtuemart.net/index.php?topic=150047.msg536124#msg536124)?
I'm not sure if it's the same problem. It happens to me that if I save the category it changes to the home page. But if I hit save and close, it stays as it was.
There was another problem a while ago, I think it was with the manufacturer in the edition of the product. You had to update with f5 to save the changes, if you gave save and close, it did not save the changes.
This topic has been discussed recently
https://forum.virtuemart.net/index.php?topic=150039.0
The problem has been fixed in version 4.0.22