during the recent New Year period
would be used to refer to the time while New Year occurred in the past. In your example is can only be referred to in the past
Almost all the shops... were closed during the recent New Year period.
However, if the New Year period has already completed but the shops are still closed, it could be described as
Almost all the shops... are closed due to the recent New Year period.
Almost all the shops... are closed during the current New Year period.
which is one possible explaination why other teachers might think "are" should be used.