@Jan.H should know serial numbers. It’s also somewhere here on forum. It’s about a year old problem.
Problem with it is that it’s caused by interference on board. That specific card has fault where it’s more prone to be affected by it. Two right slots share reference time and if one of cards generates some noise then it can affect second card if it doesn’t have sufficient filtering. Real problem is that this noise don’t have to be just from second card but also from other sources. So this can start happening just because you moved router to some spot with just right problematic interference. That is why it propagates dynamically. But it might not ever show. All boards propagating given error are requested to be sent to us for repair (as pepe wrote, capacitors change). It makes no sense to recall all routers because most of them wont encounter problem because it really depends on combination of factors. In my case for example it manifested when I tried to move a lot of data to drive (connected using SATA card). I swapped ac and g cards, ac being in left most port and since then I had no problems. But we failed to reproduce it for example with msata or other cards.
As you can see there is no guaranteed way to ensure that it won’t happen or that it happens. That capacitors replacement is more or less just hack to overcome this specific problem but when some card misbehaves then there is nothing hardware designer can do.
And why it seems to be problematic with 3.10? I don’t think that it’s. But even if it would then it’s possible that some software change just makes it more inclined to this problem. But I currently know only about one person that started having problems after 3.10. Other one in this topic encounters problems for longer time period. And I don’t know about anyone else.