Pick list contains two null values

[lexiclevenger]

Describe the bug
Bolddesk ticket from Alexis Beck at Muséum d'histoire naturelle (MHN):

I just noticed in a couple of picklists that use a field from a table to define the values that there are two blank entries instead of one.

This only occurs for the Locality -> GeoRefStatus field in the Invertebrati collection of the MCSN database. I cannot recreate the issue with any other pick list, but if the pick list is deleted and re-made, it occurs again. If the null value is selected, the selection is changed to the first null value, and the value appears as null in the API when the record is saved.

The pick list uses the 'Field From Table' type, and there are several records where the value is null, so it is possible that the database is counting null as a separate pick list item.

To Reproduce
Steps to reproduce the behavior:

1. Go to Data Entry -> Locality
2. Click on the GeoRefStatus
3. See that there are two null values in the pick list

Expected behavior
There should only be one null item at the top of the pick list as seen below.

Screenshots

GeoRefStatus pick list:

Pick List info:

Please fill out the following information manually:

• OS: Mac
• Browser: Chrome
• Specify 7 Version: 7.11.3
• Database Name: mcsn__2025_12_12
• Collection name: Invertebrati
• User Name: spadmin
• URL: https://mcsn20251212-v7113.test.specifysystems.org/specify/view/locality/new/