By setting a proxy bid, the system will automatically bid on your behalf to maintain your position as the highest bidder, up to your proxy bid amount. If you are outbid, you will be notified via email so you can opt to increase your bid if you so choose.
If two of more users place identical bids, the bid that was placed first takes precedence, and this includes proxy bids.
Another bidder placed an automatic proxy bid greater or equal to the bid you have just placed. You will need to bid again to stand a chance of winning.