It's possible you accidentally switched the settings?
Do you use a VPN? If it got routed thru a Romanian IP address, it will often try to jump to the local version of the page. It's not a yahoo thing, google and other pages will do the same.
Wouldn't hurt to run a virus scan then change the password. There is a chance you were hacked.
A quick check: We travel a lot and it's annoying to get the local page so we changed the book mark to "US.yahoo.com" That will force you to the us version. If it's still in Romanian, it's a setting issue.
