safari sometimes can't load sites or sometimes it loads sites without css I am a software developer experiencing strange errors with safari.

Sometimes safari loads some of the github.com pages without styles. The same happens with my heroku dashboard: https://dashboard.heroku.com/apps. But only sometimes.

With heroku I had much more stange errors:
'Safari can't load the url: heroku.com '

In chrome these errors never happen...
I tried to load these pages in chrome immediately when I observed the error and for my biggest surprise in chrome everything was working. (I have fiber optic huge bandwidth internet so this is a very strange question.)

Any idea is welcome.
Try restoring safari to factory default:


Settings
Safari
Delete history and data
Check the advanced tab if everything is clear, else clear it.