Unable to Dig Up Treasure in Adventures in English with Cambridge

I am playing Adventures in English with Cambridge inside Minecraft. I reached the part of the adventure where I need to dig up the treasure, but I am stuck because the game does not allow me to dig or break the block containing the treasure.

I am at the correct location indicated by the quest, but the block cannot be interacted with. I tried restarting the world, reloading the game, and switching tools, but the issue persists and prevents me from progressing.

Could you please advise whether this is a known issue, a gameplay restriction, or if there is a specific required action to access the treasure?

Thank you.