I sent it right as the pandemic was shutting things down so it took awhile to get it back. Since then it’s run fine.
After researching I noticed something that may be causing more people to have an issue that is more of a quirk imho.
If you are changing the date back a day by going counter clockwise, if you stop the hour hand before going back enough, the date wheel will not fully switch. Now it will be half way. But once you go counter clockwise enough, there is enough spring/cam(whatever they use) pressure to fully switch the date.
Watch is at 3:20am for the hour hand that controls the date. You set it to 11:20 pm. The date is stuck half way. You continue to set the hour hand back, as it snaps to each hour, somewhere around 5:20pm the date will click into place. Then you can quickly go back to 11:20pm and all is well. It never happens in the clockwise direction. There seems to be a difference in the spring power for the date in the clockwise direction compared to counter.
Side note: my polar explorer 16570 with 3185 movement is the same.
I really like these. Such a lot of watch. Hope he treasures it for years to come. Having had a deep love for watches most of my life I would love to have had either a watch bought for me or given to me by my father. I think the sentimental value would always exceed any other value. Sadly my dad was just not into watches but was still a wonderful man. I bought my own first Rolex at the age of 15. I look forward to hearing about your sons response when he receives his very precious gift from his dad. Can’t put a price on those moments. For the record I have 2 BB’s for my sons when they come of age. M.