How to immediately show the display picture?

[Tiktak]

I just noticed nodebb forum has no problem in changing the display picture immediately, but on my forum (freshly installed) I have to press ctrl+f5 to clear the cache to make the display picture to appear.

[scottalanmiller]

Are you using another cache in front of NodeBB? Like Nginx or CloudFlare?

[Tiktak]

cloudflare is not a problem because I tested that by disabling it. I use nginx, but I am not sure there is a problem with that.