New York has a rule about “convenience of the employer.” The name is misleading and doesn’t make any sense, but basically if there was no way to do the work in New York (e.g. your company sent you to New Jersey to hook up someone’s internet), it’s not considered New York-sourced income, but otherwise it is.

The issue with the current situation is that in principle I could be doing the work in New York (it doesn’t matter where I do it), but the office is closed and I don’t live in New York. So I have strong reasons for not doing my work in New York, but in principle I could be doing it there.

I guess there’s a further clause that you have to spend at least one day out of the year in New York to be taxed there, which unfortunately I have done (despite no longer traveling there for any work-related purpose).