Check TOS agreement on page reload

If the user checks the TOS agreement checkbox on a registration form but fails validation (eg. retyped password incorrectly), should the checkbox still be checked on page reload, or should they be required to reconfirm?

I've seen forms online that do require the user to recheck, but I'm not sure if there's a reason for this or if it's just poor UX.

This is related to Automatic agreement to terms of service, but concerns only form resubmit; the user is still required to check the box when initially submitting.