Not Getting Chests Anymore?

I have all my eligible chests up and haven't gotten one in AT LEAST a month.

And before anyone says "well were you punished?" I wasn't. I've never been toxic, I've never been banned or chat banned or recieved any sort of punishment besides Leaver Buster, but I've moved up a level and it has never affected my chests.

I've been playing champs I own and don't have boxes on, and people in my games have been getting S's and I have not been receiving chests. I got some of my chests on my mains by people getting S's besides me a long time ago, so it's possible (unless they changed it?).

Like recently I've played a bunch of games as Cait and people have gotten S's in my games but I have not gotten a chest. I've never gotten one on her before, and all my eligible chests are still available, and I have never gotten any punishment so it wouldn't be that...

I've also gotten a key fragment recently, so keys are fine...but I haven't gotten a chest in so long and multiple times there have been S ranks in my games on champs I do not have chests on yet.

Am I just unlucky or did they change chest drop rates or something? Does anyone else have this same issue?