Reproduction steps:
1. Open the attached “InputSystemTest” project
2. Build and run on a mobile device
3. On the device, press the “Single Unified“ button
4. Place two fingers on the ScrollRect box and scroll with one finger after the another

Expected result: The ScrollRect scrolls according to each finger motion
Actual result: The ScrollRect start jittering and jumping

Reproducible with: 1.11.2 (6000.0.22f1, 6000.1.0b5) 1.14.1 (6000.0.54f1, 6000.1.12f1, 6000.2.0b10, 6000.3.0a2)

Testing environment: macOS Sequoia 15.5 (M1 Max)

Reproducible with these devices:
VLNQA00123, Google Pixel 2 XL, OS:  11, CPU: Snapdragon 835 MSM8998, GPU: Adreno 540
VLNQA00363, Samsung Galaxy Z Fold 2, OS: 12, CPU: Snapdragon 865 SM8250, GPU: Adreno 650
VLNQA00639, Samsung Galaxy S25, OS: 15, CPU: Snapdragon 9 Elite, GPU: Adreno 830
VLNQA00624, iPhone 16 Pro, iOS: 18.5, CPU: Apple A18 Pro
VLNQA00394, iPhone 13 mini, iOS: 18.1, CPU: Apple A15 Bionic
VLNQA00359, iPhone 12 Pro, iOS: 17.6.1, CPU: Apple A14 Bionic