Modal utility window never receives Update() when using ShowModalUtility()

Reproduction steps:
1. Open project “ModalWindowBugReport.zip”
2. Open Console window
3. Open “Test\Test Window”

Expected result: an empty window is displayed and the Console is flooded with “update” messages
Actual result: an empty window is displayed, but nothing appears in the Console - the Update() method of the window is never called

Reproducible with: 2021.3.27f1, 2022.3.2f1, 2023.1.0f1, 2023.2.0a18

Reproducible on: Windows 10
Not producible on: macOS Ventura 13.2.1 (Intel), Linux 6.2.15 (by the reporter)

Note: the issue doesn’t reproduce if the window is displayed using ShowUtility() instead of ShowModalUtility()