No problems here. Another browser works fine? Otherwise: Turn off Safari’s new Advanced Tracking and Fingerprinting Protection. Check. If it does not work, leave it off and:
Turn off Private Relay and any VPN, Proxy and Safari extensions (e.g. adblocker, or any "automatic cookie agree"). Check.
If it does not work, reset the network connection. Check.
If it works, turn on the new advanced Tracking and Fingerprinting protection. Check.
Then turn on your Safari extensions etc. on again one at a time. Check for each.
If it works, turn on Private Relay. Check. Then turn on your Proxy/VPN. Check again for each.
There might be already updates for the apps (VPN, Safari extension, Antivirus, et cetera) involved.
—————————
If the above does not help, folllow
@CMoore515 ’s advice. Check.
If that does not work, follow
@Apple_Robert ‘s advice.