Reproduction steps:
1. Open project in "NputYstem.zip (26.4 KB)"
2. Open SampleScene and build for iOS
3. Deploy the Xcode project generated to an iOS device
4. Rapidly tap on the button for a few times (Note 1, 2)
5. Inspect the button

Expected result: the button is not being pressed (Note 3)
Actual result: the button is being pressed (Note 3)

6. If the issue does not reproduce, repeat steps 4, 5 until it does (also watch the video attached)

Reproducible with: Input System 1.0.0 April 29 2020 (2019.4.7f1, 2020.1.1f1, 2020.2.0a20)
Could not test with 2018.4 because I couldn't make the buttons work with 0.2.1 - preview

Not reproducible with built-in Input Manager
Not reproducible in Standalone build (tested Mac)

Devices tested:
Reproducible with:
VLNQA00310 iPad Pro 12.9 1st gen (iOS 13.4.1)
OnePlus A5000, Android 10, Adreno 540, Snapdragon 835

Notes:
1. Video is attached (VID_20200803_161734.mp4 (25.4 MB))
2. To rapidly tap on the button it is best to use multiple fingers
3. It will be visible by the color that the button is being pressed, however, any actions bound to that button will also be executed so this is not a cosmetic issue (OnPointerDown is executed)