The behavior matches a mismatched-accounts scenario between the Microsoft Store account (which owns the Bedrock license) and the Xbox/Minecraft playing account.
To avoid being asked to buy again and to stop needing two accounts signed in at once, the game needs to be run with a consistent identity strategy:
- Decide which Microsoft account should be the purchasing account (the one that actually owns Minecraft for Windows/Bedrock in Microsoft Store order history).
- On Windows 10, open the Microsoft Store app and sign out, then sign back in with that purchasing account only.
- In the Xbox app/Xbox Game Bar, sign out and sign back in with the same Microsoft account if the goal is to keep purchases and play identity aligned.
- Launch Minecraft for Windows from the Microsoft Store “My Library” section so it uses the Store account that owns the license.
If the design of the game or services assumes that the Xbox account and Store account are the same, then both apps (Microsoft Store and Xbox) must be signed into the same Microsoft account; otherwise, the game can treat the Store account as the payer and the Xbox account as the playing identity, but it must explicitly support that mismatched scenario.
If, after aligning accounts as above, the Store still shows only a “Buy” button and no “Install” option for Minecraft for Windows on the account believed to own it, then the Bedrock license is not currently associated with that Microsoft account, and support would be required to review purchase history and account ownership.
References: