I think you’re going to have to do this to solve your issue:
• Fully quit the sim (I suppose that is precisely what you’re getting after a CTD…)
• Press Xbox Home button
• Highlight FS2020 & press Menu
• Select Manage game and add-ons
• Highlight Saved Data & press A
• Highlight Reserved Space & press A
• Select Clear Reserved Space
Important: This will clear the sim of all add-on content including World Updates and/or Deluxe/Premium content, all of which will need to be redownloaded. It will also clear all your custom camera views and bush trip progress. However, if you’ve gotten a corrupted download (Seafront, as you stated), you’re stuck anyhow, because you can’t even launch the sim, but this will fix that. I had to do this procedure to be able to complete the SU8 (yes, 8 not 9) in-sim download content, because the sim kept crashing on me.