Steps to reproduce the problem:
The problem is reproducible using hash-based and history API-based navigation.

Use attached history.html or go to https://app.mimernotes.com/history.html to test hash-based case

Use attached history-api.html or go to https://app.mimernotes.com/history-api.html to test history API-based case

What is the expected behavior?
Hash-based:
Loading page in a new tab and clicking browser back-button twice the expected output would be:

new url: https://app.mimernotes.com/history.html#1
new url: https://app.mimernotes.com/history.html#2
new url: https://app.mimernotes.com/history.html#1
(browser navigates back to new tab page)

History API-based:
Loading page in a new tab and clicking browser back-button twice the expected output would be:

state: {"screen":"1"}
state: null

What went wrong?
In both cases Chrome on iOS goes back to the new tab page without triggering the expected history states.

Did this work before? No 

Does this work in other browsers? Yes

Chrome version: 69.0.3497.71  Channel: stable
OS Version: 11.4.1
Flash Version: 

Also tested with Safari on iOS producing the expected behavior, the problem relates only to Chrome on iOS which seems to handle history states differently.
 

Deleted: history.html 504 bytes

history.html 504 bytes View Download

Deleted: history-api.html 561 bytes

history-api.html 561 bytes View Download