Hi Bernadi, thank you for using our forum, my name is Luis I am part of the Small business Support community. I have some question for you:
1.1) What kind of computer are those that didn't work?
1.2) If you connect those, are you receiving an IP address from DHCP?
1.3) What gateway is showing?
2.1) Do you have any debug or error?
2.2) Did you try creating an Forwarding rule for 443 to the server address?
I recommend you always use the last firmware.
I hope you find this answer useful
Greetings,
Luis Arias.
Cisco Network Support Engineer.