From
https://bike.shimano.com/en-US/information/news/shimano-12-speed-mtb-cassettes.html
The new technology relies heavily on the chain, so if you want the true HYPERGLIDE+ experience, you'll need a Shimano 12-speed chain to go with your 12-speed cassette. With this combination, the newly redesigned cassette smoothly guides the chain up and down the cogs, providing faster shifting in both directions. The chain itself also features an extended inner link plate that connects seamlessly with the new cassette tooth shapes, making it Shimano's most efficient drivetrain ever.
NFI what that actually means, other than Shimano Hyperglide+ chains might be a bit funky on the inside. As RF has Shimano
12-speed specific rings, it suggests that Pushy’s needs to clarify that “12 speed compatible” doesn’t include Shimano 12-speed for for ring that
@takai purchased. Perhaps flick an email to RF confirming this, then contact Pushy’s to claim false advertising and have them swap it over to the right one or refund you? They’re usually pretty good with returns.