@bmx666 Thanks for the response.
After more digging the past few days, it seems to be the case after OSX update. I am having an issue with Chrome as well. I have enabled local private access for Opera but still unable to connect to local address.
The frustrating part is not the blocking. It's the page to allow me to continue at my own risk is not even showing up by default anymore.
Safari works with the warning page which allows me to continue.
Both Chrome and Opera simply block page stating unaccessible. This behavior is the main complain. I have tried so many config changes in Opera and it simply won't work.

finds.synolog.com can be able to find the device in Opera:

but clicking on it simply says:

Clicking on the "globe" icon next to the url bar get me to some browser configs, but nothing will trigger the "continue at your own risk" page to show up.

How to unblock inscecured local ip address access?
This is really dumb. I can't even get the "proceed with your own risk" to pop up anymore. The browser simply automatically block the local ip.
I want to access my synology via local IP so the transfer is faster than via DDNS.
But Opera is so anal about this. Any idea how to do this?