Why does STM32H723VGT6 crash at startup if Timebase Source is not SysTick when using CubeIDE 1.9.0?

[Alexu]

Steps to create on my system (no user code required):

1. Create a project for STM32H723VGT6 using the New Project wizard. Accept all default settings.
2. Build - Download to Target - Run. Everything works as expected.
3. Open IOC file. Go to System Settings->Sys and change Timebase Source to a Timer module (I use TIM6 but all appear to fail).
4. Re-build - Download to Target - Run. The code gets stuck in an infinite loop immediately after the Timer interrupt is enabled.

This works correctly on CubeIDE 1.6.0, so what has regressed on 1.9.0?