Greetings, Aminatuu.
Welcome to the Apple Support Communities. We can understand why you’d want to figure out what’s causing the damage to your iPhone.
You mentioned using Dettol wipes. Per Apple: “Your iPhone has a fingerprint-resistant oleophobic — oil repellent — coating. Cleaning products and abrasive materials will diminish the coating and might scratch your iPhone. ” Cleaning your iPhone
At this point it would be best to Contact Apple Support to explore your options.
We hope this helps! Thank you for being a part of the community.
Best wishes.