Can't Access files

Well, I have never faced something like this.
I have this folder (Let’s call it ‘aa’ folder) in Public_html folder of a website, which is hosted on CyberPanel. (Hetzner Cloud)
I used to link the images hosted on this aa folder with my emails.
All of a sudden, I noticed my emails stopped picking those image.
So, I checked!
I no longer can view the images hosted on aa folder.
But, when I check through the file manager, aa folder and all the files are there, as they were.
Can anyone suggest a solution to correct this?
Thank you