XPS 9320 BIOS 2.28 caused touchscreen failure + 30 sec boot delay (I2C HID Code 10 / ACPI\CUST0000)

After updating my Dell XPS 13 Plus 9320 to BIOS 2.28, the touchscreen stopped working.

Symptoms:

• I2C HID Device Code 10

• “A request for the HID descriptor failed”

• Hardware ID shows ACPI\CUST0000

• POST/startup now pauses 20–30 seconds every boot with “your device will take longer than usual”

• BIOS does not retain touchscreen disable setting after reboot

Tried:

• BIOS factory defaults

• BIOS recovery/reflash

• Intel Serial IO + HID drivers reinstall

• EC reset/power drain

• reinstalling HID devices

Touchpad recovered, touchscreen still dead.

Did anyone else get this after BIOS 2.28?