Yeah, two Colts players and a lot of Lions players mainly. Mostly guys whom were probably practice squad players. But one player from each team whom clearly would of man the roster.
The Colts CB Rodgers, biggest win was $1,000 that some Colt player would get 100 yards in a game. Supposedly most of his other bets were $20 and $50, but he was betting on the NFL games.
Also there are a few others, like I believe Titans RT, but that wasn't fully year. According to the RT, he legally gambled on NON-NFL items... which would of been acceptable, had he not been on NFL/Team property when he did it. He knew gambling on NFL games were banned, but did not realize all gambling was banned while on Team Property.
Which reminds me, all Alcohol is banned from Team Property and travel too ... and yet, reports suggest most teams have some alcohol.
In other words, the NFL turns a blind eye to most things, except when it's caught red handed. Examples include
Andy Reid's son getting drunk on Chiefs property and then DUI crash killing people (no one has confirmed where the alcohol came from, just that he was drinking alone... but they have refused to say he was the one that brought the alcohol in, which suggest he wasn't, as they were nicely and professional throwing him under the bus (while trying to not upset head coach Andy).
QB Taylor Heinicke got caught holding an open beer on the team plane after a win, I assume a teammate, took a celebration picture and uploaded to social media. NFL was outraged as alcohol isn't allowed on team travel like planes. Heinicke (and others) suggested that alcohol is always on travel, maybe not before the game, but certainly flowing after the games, and they don't have to hide it on team travel.
Marshawn Lynch, claims he always had a couple of shots before games to knock off the nerves and always had some with him, and everyone knew.
My point being, the NFL doesn't care about the rules... they only care about being caught and bad PR. And possibly only enforcing the non-NFL betting now because it's bad PR and they got caught with some players betting on NFL games (which they probably do care about actually NFL games).
But I'm willing to bet that some of these owners and team management couldn't pass the same drug tests that players have to pass. And the some of them surely have bet on non-NFL games while on team property. Maybe even some betting on NFL games (though not electronically like the players), but more verbal bets agreements.