Foreclosure Sales In FL

I have a question regarding foreclosure sales in FL. I have been learning and watching the online auctions in South Florida done by the county. I seen a situation that I want to understand the outcome. I noticed that there was a property being auctioned because of unpaid HOA fee’s of like $9500. There were no other liens on the property, property tax show paid on time each year. One mortgage that I assume was getting paid since nothing was filed by the bank. A 3rd party bidder own the auction for $12,500. Lets say the winner now files for writ of possession and files quite title action. What happens to the mortgage on the property will the winner be responsible for it or does the bank lose out since they didn’t show up at the auction? Can the bank still turn around and file lis pendens on the new owner (auction winner)? I have seen this more than once, more and more HOA’s are foreclosing on owners.

Basically if it’s not the bank foreclosing on the property and they don’t show up at the auction or file anything what happens to the mortgage?