BLHeli Programming Suite with Flycolor X-Cross v3

I’m trying to program a Flycolor X-Cross HV3 160A (5-12 S BLHeli_32) ESC for my foil-assist build, but I can’t get BLHeliSuite32 to talk to it.
Here’s my setup and what I’ve tried — maybe someone here has run into the same thing.

Setup

  • ESC: Flycolor X-Cross HV3 160A (BLHeli_32 / DShot / ProShot, 64 MHz MCU)
  • Power: 12 S (2 × 6S3P Molicel P45B)
  • USB linker: FlyingTech ESC USB Linker Programmer (CH340-based)
  • Software: BLHeliSuite32 v32.10.0.1 (and also tried 31.10 & 31.9)
  • Interface: BLHeli32 Bootloader (USB/COM)
  • COM port: COM3 (“USB-Serial CH340” in Device Manager)

Symptoms

  • ESC powers up normally → beep-beep-beep startup tones.
  • Linker LED flashes once when I click Connect or Read Setup in BLHeliSuite32.
  • Then I get “Connection to ESC failed.”
  • Measured with Multimeter between signal (yellow) and ground (black) on the servo connector wire → 0 V (flat)

Looking for advice

  • Should there be a constant 3.3 V idle voltage on the PWM signal pin when powered?
  • Any other ideas why the signal line would stay dead even though the ESC boots and beeps normally?