Version 67.0.3376.0(Official build) dev (64 bit)
Platform 10520.0.0（official build) dev-channel link 
Firmware Google_Link.2695.1.169

REPRO STEPS:
1.Switch to Floating keyboard
2.Lock screen
3.Focus on the Password-input box of the LockScreen.
4.Switch to UK keyboard
5.Open VK's menu list
6.Slide to select US.

Actual result:
Cannot slide up to make "US keyboard" appear.
After switch to any another keyboard, the "US keyboard" appear again.

Note:
This issue only repro with UK keyboard.