Just double checking, what version of Breadcrumb NavXT are you using (for both the export and the import). Back in 7.3 a similar issue was fixed (see https://github.com/mtekk/Breadcrumb-NavXT/issues/289), so depending on the version you are using, it may already have been fixed or was missed somehow in those changes. None-the-less, I’ll see if I can reproduce this specific case in my testbed.
Curious if you get the same results.
We have the plugin Network Activated in a Multisite environment if that matters.
{
"plugin": "Breadcrumb NavXT",
"version": "7.4.1",
"settings": {
"bmainsite_display": false,