UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36

Steps to reproduce the problem:
1. In any console, enter:

let property = 'salary_rules[nil36378820000][description]'

2. Then enter:

let idRegex = /^salary_rules\[(.*?)\]\[(title|description)\]/g;

3. Now enter the following repeatedly:

idRegex.exec(property)

What is the expected behavior?
A match is returned each time.

What went wrong?
A match is returned every other time, even though neither the regex nor the string is changing.

Did this work before? N/A 

Chrome version: 66.0.3359.139  Channel: n/a
OS Version: OS X 10.12.6
Flash Version: