It seems that some online stores are selling "Upgrade Kits" that include New generation CPU's but with last gen "compatible" Motherboards. Which, in all technicality, is a good way to move older stock and since its still supported. No issues... Right? With both Intel and AMD upgrade kit options, a good amount of very budget friendly and darn good spec bundles include the latest Gen CPU's with the last Gen Supported Motherboards. The issue is they sell these upgrade kits without Properly warning the buyer that their new CPU and Motherboard are NOT compatible out of the box.
These kits assume you are upgrading from a 1st or 2nd gen Ryzen to a 3rd Gen and can update the BOIS to a betaBIOS which supports your new CPU using your old one, and similarly with Intel. Most commonly with "B" series Motherboards. However you may very likely be upgrading from a 6th gen Intel to the New Ryzen 7 3700X or whatever... and CANNOT update the BIOS yourself.
I am a PC technician and see this too often where no one can assist the buyers to get their new Components working, since not many stock 2nd Gen Ryzen to be opened just to update a BIOS.
If you are considering to purchase any of there 'Upgrade Kits" please do a bit more research whether you may even be able to use your new tech.
Edit: Also just found this: