Partitions Not Appearing In Finder Sidebar

[JoelBC]

I have an external SSD drive with 4 Partitions.

When I connect the external drive to my MacBook:

1. All 4 of 4 partitions appear in Finder when I select my MacBook;

2. Only 3 of the 4 partitions appear in the Finder sidebar; and

3. Were I to manually add the missing partition to the Finder sidebar and then reboot the MacBook that added / 4th partition is no longer there and needs to be re-added.

Please let me know how to fix this.

Thank you.

 

[NoBoMac]

Is the partition encrypted? If so, checking the "save in Keychain" box when entering the password?

 

[JoelBC]

Appreciate the suggestion but none of the partitions are encrypted.