there is another possibility especially on the holiday;
high security checks must be "called in" to the bank to be valid for cashing "completely prevents forging"
someone might have missed a cut-off time to "call in" and activate your check,

I hear this on Saturdays "this check will not be valid til Monday at 11:00AM"
now of course if you take it to an old school Mom&Pops check cashier with out computer access, and they don't try and deposit the checks first thing Monday morning you are golden



V/r HT1