passport cancelled due to being stolen is my visa still valid.

My passport was stolen in January and has since been returned to me. I have a new passport and have been led to believe that my visa in my old passport is still valid because I never contacted the US government to cancel it.

It a passport expires the visa is still valid, is it the same if the passport is cancelled?

If an immigration officer looks-up your visa, they would find that passport has been marked as lost. That may cause an issue. Had it expired, look-up query would have returned as expired, which is not an issue.

IMO, b/c the old passport is marked as lost, you should not use it’s visa stamp. Either mark your passport as “not lost”, or get a new visa stamp.