When you are bidding & you hover your mouse over the possible bids during the auction phase, you get an explanation of the bid. For e.g. in Response to 1NT by partner, when it's your turn to bid, & you hover your mouse of 2♣, you get an explanation & that 2♣ is Stayman. Occasionally, there is no explanation (in a bid where there should be) - you just see "Loading explanations ..." & nothing else happens after that. I haven't been able to get a screenshot of that but here is a screenshot of what happens after you click anyway on a unexplained bid. If you check this auction, both 1♥ & 2♥ are bids which have a proper explanation. However, for 2♥, it say "loading explanations .." & after I bid 2♥, shows the bidding screen with both the bids not highlighted. Non-highlighted bids are bids where you don't have an explanation. Here in this case, I think there is an explanation for both 1 & 2♥ but it's still not highlighted. Is this a bug? This occasionally happens for some bids.