China 2813 date goes too far

[chriz74]

It’s been two days in a row I found the date on the watch at half position, eg from 9 to 10 results in between 10 and 11. However changing date by hand everything is normal. Clues?

[watchweasol]

Hi  faulty detent  broken detent spring or worn day wheel not pushing the day fully over the detent, all possibles