iOS Chrome Resizes window when form is selected + keyboard exited

I'm presenting a login modal using this lib, it's a baffling bug that only occurs on Chrome on iOS. It's PROBABLY a Chrome problem, tbh, but any help would be appreciated...

`{this.hideRegisterModal(false);}}
initialFocus="#close-button"
getApplicationNode={this.getApplicationNode}
underlayClass="demo-seven__underlay"
dialogClass="expertRegister-modal-background"
includeDefaultStyles={false}
key="onboarding-modal"
ref={c => this.container = c}
>`

Here's the code in .jsx ^

And CSS:

` // MODAL STYLES
.demo-seven__underlay
position: fixed
top: 0px
left: 0px
bottom: 0px
right: 0px
background-color: rgba(0,0,0,0.5)
z-index: 2`

`.expertRegister-modal-background
position: fixed
top: 5px
left: 5px
bottom: 5px
right: 5px
z-index: 3
overflow: scroll
background-size: cover
border-radius: 5px
box-shadow: 0 2px 10px 0 rgba(0, 0, 0, 0.5)
background-image: linear-gradient(151deg, rgba(231, 61, 74, 1), #e73d8b)`

Here's what it looks like:
Keyboard presented:

Keyboard hidden:

What's annoying is, for the rest of the app any time I present a modal (with form field) it renders like this (50% or so of the height cut off). And this area isn't scrollable really. It's a bizzare bug.

Thanks