Hey Jurman,
Are you able to replicate the issue on different devices/browsers?
If not, it’s likely a cache issue with your browser, try clearing cache and cookies by clicking the 3 dots on the top right -> more tools -> clear browsing data -> cache and cookies for all time and you should be all set
If you can replicate, try changing the background skin back to default and then back. See if the issue persists.
Hope this helps