Steps to reproduce:

1) Download attached project and open in Unity
2) Play the Menu scene
3) Try writing numbers in Object Count: field
4) Notice only first input digit is shown (sometimes second as well)

Expected result: Whole number should be saved after keyboard is closed(check attached video 'noRepro.mp4')
Actual result: Only first digit is saved after keyboard is closed(check attached video 'repro.mp4')

Reproduced with:
2017.2.0b1, 2017.2.0f3, 2017.3.0b6, 2018.0a1

Not reproduced with:
2017.1.2p2, 2017.2.0a1, 2017.2.0a4

Regression since:
2017.2.0b1

Devices under test:

(5036) Sony SGP771*, OS:6.0.1, CPU:arm64-v8a, GPU:Adreno (TM) 430
(0105) Verizon SM G930V*, OS:6.0.1, CPU:arm64-v8a, GPU:Adreno (TM) 530
(0096) Xiaomi Redmi Note 3*, OS:5.1.1, CPU:arm64-v8a, GPU:Adreno (TM) 510
iPad Mini 2 iOS 9.2