There is a problem that may be from server side. Do a couple of traceroutes and follow steps in here as provided to help identify (or reconfirm) the issue:

https://us.battle.net/forums/en/d3/topic/20769578452

All those who are still suffering from this issue, please do report to them on the thread as per the link from my first reply.

Your Traceroute result as well as the MTR report would help them speed up the fixing process (hopefully).

Character progression are separate for each region. I might also have to check out Asia server for the moment as it has been more than a week since this issue started...

For SEA players like us, Asia server has the best ping. Anywhere between 70 - 150. The only reason I've not played there as often is because I started off in The Americas since Day 1 of Diablo III and I find it hard to do it all over again in Asia (Achievements, etc.)