Hi SilkchenGermany
It’s usually the cache, either on your server, web browser and in most cases your ISP.
So if you reboot your server, unless of course you are not hosting your wordpress, ask your hosting company to flush the cache for you.
clear all of your cookies, if still no luck then it’s your ISP, you will have to wait few days for the cache to renew.
There’s nothing more annoying than the cache, it is equally useful but very annoying at the same time, especially when it’s your ISPs which you won’t have access
Or check with your friends after you made any changes ask them to load your site and see any changes, they should see the changes.