Reproduction steps:
1. Open the attached “BugRepro” project
2. Open the “Assets/Scenes/SampleScene“ Scene
3. Enter the Play Mode
4. In the Game View, open the DropdownField at the top of the window
5. In the DropdownField drawer, Select the blank (single space character) option
6. Observe the Console

Expected result: No errors are logged in the Console
Actual result: “IndexOutOfRangeException” error is logged in the Console

Reproducible with: 2023.3.0b4, 2023.3.0b10
Not reproducible with: 2021.3.36f1, 2022.3.21f1, 2023.3.0b3
Couldn't test with: 2023.2.13f1 (the blank (single space character) option does not get added to the DropdownField)

Reproducible on: Windows 11, macOS 14.2.1 (M1) (By user)
Not reproducible on: No other environment tested