Howard Miller Wall Clock doesn't chime 12

by Holly
(Indianapolis)

My Howard Miller wall clock is running fine, keeping good time, but when it is 12:00, it only chimes either 10 times or 11 times.

It chimes correctly for all quarter hours, half hours, three-quarter hours, and all hours except 12.

I have tried going around the clock manually, letting it chime through each 15-min interval for every hour hoping it will re-set it or something, but when I get around, back up to 12, it won't chime all 12 times...

I appreciate any insite with this, thanks!