Scab inside of left nose not healing

Hello All,

I have a scab inside my left nose for the last couple of months that won't heal. It's on the mucous membrane. I reached out to my doctor who later referred me to an ENT, but their treatment is not working, so I'm looking for someone who experienced this before and could perhaps help me out. They think it's just dry nose.

At first I noticed the scab when I was blowing my nose and saw dried blood and felt stinging. When I looked inside my nose with an otoscope, I saw the attached pictures, which I sent to my doctor. He said it's an infection and put me on a 10 day Mupirocin ointment with instruction to keep it moist for a week after that antibiotics course is done. So I applied saline gel every two hours for a week straight, but as you can see from the pictures the scab is back at full force, so I don't think it's related to dryness, but I'm not a doctor.

Here is a description of the pics:
Pic 1: before the Mupirocin treatment started
Pic 2: halfway through the treatment
Pic 3: after the Mupirocin treatment ended
Pic 4: now

Any help would be appreciated.

Thank you.