Greeting everyone. I tried few different solutions like disabling IPv6 which cause Eddie to freak out and restart the connect since it will try to reattempt to connect IPv6.
After looking around and found a right solution for this issue. It is something to do with the gateway that OpenVPN don't have the support for. Office 365 and Microsoft product relies on gateway for detecting network activity. The way Eddie/OpenVPN are designed to keep the gateway blank is the cause of the issue. The I found the solution from this forum, Here is the link to the actual solution of the problem. I can confirm it finally working with Eddie running.
https://www.macwheeler.com/windows-10-office-365-cannot-connect-over-openvpn-fixed/
It like what JimDandy posted. The guide recommend putting 192.168.0.1 in TAP's gateway in IPv4 Advanced option. The link have the guide step by step how to do it. I can confirm it works for me. And I haven't got any complaints from OneDrive and Office 365 with this guide.
Edit: One last thing I forgot to add in this comment. Generally the default gateway is 192.168.0.1, there is a few routers which will use a different address. I have T-Mobile Personal Cellspot TM-AC1900 (rebranded Asus AC1900) which use different gateway address in my case, it is 192.168.29.1. If it didn't work with the common default gateway address (192.168.0.1), then it is likely it have a different gateway address. If you need to locate it, do not activate the VPN because it will show blank. For Windows, go to PowerShell (or CMD), then type "ipconfig" without the quote. Then look for "Default Gateway", you will see the IPv4 address at the end of it. That is the address of the default gateway.