Hi – I’m sorry to hear you are experiencing difficulties.
We’ll happily take a look at this, but can I ask you to distil the problem down to a set of steps to help us reproduce (unfortunately I’m not familiar with this plugin and I’m not sure which custom field data you might be referring to). Certainly I’m not seeing an issue with the password or link label fields being wiped, and the custom post type established by that plugin does not appear to support conventional custom fields, but perhaps you are referring to something else?
Thanks for clarifying!