How to reproduce:
1. Create a new project
2. Install the new Input System and restart the Editor when prompted
3. In the Project panel create a new "Input Actions" asset
4. Select the created asset and in the Inspector press the "Edit asset" button
5. In the window that opens up create a new control scheme
6. In the "Action Maps" column create a new action map
7. In the "Actions" column open the "New Action" item and select the "<No Binding>" item
8. In the "Binding Properties" column under the "Binding" category open the "Path" dropdown

Expected result: the dropdown shows input options
Actual result: the dropdown is empty and rendered as a white square

Reproducible with: 2021.2.16f1, 2022.1.0a12, 2022.1.0b13, 2022.2.0a8
Not reproducible with: 2019.4.35f1, 2020.3.30f1, 2022.1.0a11

Reproducible on Ubuntu 20.04
Not reproducible on Windows 10