Here's what we know:
* The cause: This glitch is related to a programming error within the game itself. It's a rare bug, but it can occur in specific scenarios.
* Impact: The reappearance of the card is purely a visual bug and doesn't affect your progress or gameplay. You can still continue playing and collect other cards.
* Workarounds: Unfortunately, there isn't a guaranteed fix for this specific bug. Some players have reported that restarting the game or loading a previous save can sometimes resolve the issue, but this is not always effective.
If you're experiencing this issue, here's what you can try:
1. Restart the game: Exit and re-launch Sonic Adventure DX.
2. Reload a save: Load a save from before completing mission 54 and try playing it again.
3. Verify game files: If you're playing through Steam, make sure your game files are intact by verifying the integrity of the game cache.
4. Update drivers: Keep your graphics drivers updated to the latest versions.
5. Check for mods: If you're using any mods for Sonic Adventure DX, try playing without them to see if the bug persists.
While it's frustrating to encounter glitches, remember that they are a common part of older games, and this specific one doesn't affect your ability to enjoy the game. If the bug persists, you can try reaching out to the game's community forums for potential solutions or reporting the issue to the developers.