Why can I only play the trial version of Minecraft: Xbox One Edition

Minecraft Xbox One Edition as discontinued years ago for the Bedrock update.

https://support.xbox.com/games/game-titles/minecraft-version-differences

Playing Minecraft between devices and platforms

You can play Minecraft: Windows 10 Edition with other devices running Minecraft: Pocket Edition, such as Windows 10 and Windows Phone devices.
If you have Minecraft: Apple TV Edition, you can play locally with other players running a version of Minecraft: Pocket Edition. Visit Minecraft: Apple TV Edition overview
for more info.

Minecraft: Xbox 360 Edition can only be played with other Xbox 360 consoles on Xbox Live. The Xbox One edition can only be played online with other Xbox One consoles. There is no cross-platform play between the Xbox editions and other editions of Minecraft.

Minecraft: Xbox 360 Edition can only be played with other Xbox 360 consoles on Xbox Live. The Xbox One edition can only be played online with other Xbox One consoles. There is no cross-platform play between the Xbox editions and other editions of Minecraft.

For more info: https://support.xbox.com/en-US/games/game-titles/minecraft-version-differences

There are several different versions of minecraft. Minecraft: Java edition is PC only and can only crossplay with Java players (mac, Lenox, PC) The minecraft that doesnt have a version next to it is the play together version or more commonly called bedrock.
Bedrock is the version that can be played across mobile, console, and PC. There are also editions that are made specifically for most consoles and even a stand alone mobile version. Examples would be Minecraft: Xbox One Edition, Minecraft: Pocket Edition.
These do not work with Bedrock which is just called Minecraft. Java is the most updated version of minecraft while bedrock would be right behind that one. The others I'm really not sure how often they update them if at all. Each edition of Minecraft has to
be purchased separately. I happen to own both Minecraft: Xbox one edition and Minecraft since they released at separate times. I also have Java on my PC. As for your issue they do not have a Bedrock version on the 360.

U should check if u own Minecraft Xbox one edition check if it has a popup that says

u have been playing Minecraft Xbox one edition for Certain days u can get this new Minecraft for free

And once u tap to get Minecraft u will be redirected to the Xbox store Minecraft will be free

That's how I got Minecraft free

I don't get anything, I know I've had hundreds of hours in Minecraft xbox one edition. It might have been through another profile owning it on the same console in the past. Regardless it should either say "owned" or "purchase price". But it all it says is
"get trial".

I don't want a trial.. or this new free Minecraft.

Why is this so difficult.. I just want the original xbox one edition minecraft where I can continue my saves and achievement progress.