Thought I'll just do a post to help other folks with a similar setup as mine.
This post may benefit you if your setup looks something like:
1. Using M1 fibre broadband, with voice service bundled
2. Setup consists of the ONT (using Huawei HG8240), and RG (using Huawei HG256)
Non-M1 users, kindly refrain from clogging up the thread.
I hope to keep the thread useful and informative for everyone.
Will attempt to keep the info up-to-date within first 5 posts.