Hello Audrey Turley,
Thanks for letting me know.
That actually give me an idea of how this could go.
While Mojang account has been migrated with Microsoft Account, the order history of the 2 platform still remains separated. If you bought the game from Minecraft.net, then it won't show up on your Microsoft order history.
After the migration, the Microsoft Store will be in charge of any real money purchases, including coins and packs. Those purchases will appear on your Microsoft account order history. The packs you bought using Minecoins after that usually don't.
In this case, can you please try to download the game directly from Minecraft.net to see if it recognize your license? You can also find the Minecraft Launcher in the Microsoft Store (It's a free launcher), download it and log in with your account to see if you can play the Java edition from there.
I'm waiting for your reply.