We don't know why YOU didn't see it, but it doesn't matter why or if. You are never guaranteed a rebid. You are never guaranteed notice of being outbid in time to act on it.
Bid your TRUE maximum that you are willing and able to pay for that particular item as listed (don't forget to back out shipping etc.) WITHOUT REGARD to what others appear or don't appear to have bid. There is absolutely no need to figure out what others have or haven't bid or might bid* in determining your bid amount, since it ALREADY will have been figured into the price if you win. While some claim tactical reasons to place a lower bid early in the auction and then wait until near the end to bid your full TRUE maximum, I advise bidding only 1 time (can't repeat it enough: at your TRUE maximum) because you are never guaranteed a rebid (and there are circumstances where the prior bid prevents a rebid on that same auction). For several reasons later bidding is better than early bidding (doesn't use up your Limits, keeps your options open, doesn't leave your hidden maximum available for others, including dishonest sellers, to probe by "nibbling" at it) and I recommend using a third party "snipe service" (do a websearch, there are reliable and secure ones that are free for limited use or there are different fee schedules that best suit your bidding quantity and ratio of wins) to place your bid during the last few seconds using eBay's API rather than the not especially reliable web interface or, worse, mobile app.
*(other than to assume someone else will value the item about the same as you, so bid a bit ABOVE any round or roundish number you come up with to increase your chances of being on the winning side of what might have been a tie or a loss to someone else who knows this tip)
