Realtime Reflection Probe shows an error in the Inspector

Steps to reproduce:

1. Create and open a new URP 3D project
2. Create and select a Reflection Probe GameObject in the Hierarchy
3. Set its type to "Realtime"
4. Open Edit -> Project Settings -> Quality
5. Enable the "Realtime Reflection Probes" setting
6. Observe the Inspector of the Reflection Probe GameObject

Actual results: An "The associated texture is not a Cubemap." error is displayed at the bottom

Expected results: No error is displayed in the Inspector

Reproducible with versions: 6000.5.0a6, 6000.5.0b6, 6000.6.0a4

Not reproducible with versions: 6000.0.73f1, 6000.3.14f1, 6000.4.5f1, 6000.5.0a5

Tested on (OS): Windows 11 Pro (25H2), Ubuntu 24.04

Notes:

• The complete error reads: "The associated texture is not a Cubemap. If the texture is backed by an asset this can be fixed by setting the texture type to Cubemap in the texture importer and then rebaking the probe."
• There is no way to resolve the issue, as there is no texture associated to it within the Inspector
• The issue primarily appears to be only visual, nothing seems to be affected functionally
• The error appears after enabling "Realtime Reflection Probes", however after disabling the same option, the error does not disappear