What is the number beside arrow keys?

it’s the number of picture and the current one. Here you have 1/7 pics
You should add “/” in the colorbox options
In “interface” > grouping labels
you write add “/” inside the second case

I’m personaly searching how to delete this thing so it doesn’t appear, if you have any idea…

Ahh thanks!

Can you resolve this if you have your question answered?

ok!