I've been wondering about this for a while and a good guy said that the filters used in the betting history should be fixed in a test mode at the end of the week (and it will take a few more days to release an update that will fix the related problems if they arise).
Most likely you are right as it has been my guess, too, like expressed here. Probably I would just need to customize my timeframe to year 54754 and these bets would display again.
However, successful bets are giving rewards, so it's really just a displaying problem.
No hurry for Betnomi, as I know the devs are busy and solving that display issue until Word Cup would be perfect for us.