The Valjous 7750 series have the chronograph as an integral part of the movement. This, IMHO, makes it a PITA to service. Regardless of the servicing issue, they designed the movement to be economical to manufacture. Hence, the minute register has a jumper spring that synchronizes the counter hand with the sweep seconds hand. So, the counter advances one step every time the sweep hand passes zero. Conversely, the hour register is gear driven without a jumper spring. This, of course, leads to the misconception that something is wrong with the watch which is not the case. the observed operation is quite normal. My SA works as you described. The only reason I can think of for the operational difference is economy of production.
On the other hand, the chronograph on the ETA 2892 series is a modular unit coupled by a single wheel from the movement. This makes servicing much easier. The watchmaker can work on the movement and the chronograph individually. It is much easier to detect and fix problems.
Regards,
Onewatchnut
_________________ 1809 Cosmonaute 1903 Navi Navi Olympus Super Avenger
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