The growing U.S. sportsbook industry is starting to learn lessons other operators had to learn years ago. Several books had to fight glitches and downtime during Super Bowl LV, unable to handle the peak-day load of volume.

BetMGM, FanDuel, DraftKings, BetRivers and Barstool Sportsbook each had their own flavor of problems on the big Sunday. Many of the problems seem to have originated with Kambi, who suggested the problem was with a high volume on a specific player prop.

“This specific problem was quickly identified and rectified ahead of kick-off, at which point Kambi processed the highest ever bet volumes in its history,” the spokesperson said. “Beyond this specific issue, all systems responded within acceptable performance limits.”

That helps explain some of the issues faced by DraftKings, BetRivers and Barstool, but not the others. Flutter’s FanDuel reported an outage in Michigan and Illinois affecting both logins and wagers, and BetMGM tweeted their own issues: