Example, this Aug 2021 article:

"Connecticut, Delaware, Nebraska, New Jersey, New York, and Pennsylvania have a “convenience of the employer” rule, which states that if the employer requires the employee to work in another state (i.e., for the employer’s convenience), then withholding is only taken in the location where the work is performed. If, however, the employee chooses to work in another location—i.e., for the employee’s convenience—then withholding must usually be made in both locations. (The employee may escape double taxation via a state income tax credit.)"

Doesn't mention the Oct 2021 change.