Changed ISP now our online booking is not loading. What's the issue? SSL or static IP?

Changed ISP now our online booking is not loading. What's the issue? SSL
or static IP?

We switched internet service providers from ATT to Comcast now our online
booking software is not loading. It does work in the server though but not
in any other computer. The online booking is set-up with an SSL
certificate and we did have Comcast give us a new static IP address. Since
our online booking is set-up under a sub-domain I updated the zone file to
point to the new static IP, I thought this would work but it's been about
24 hours and the page still won't load.
I've never really done this so I'm not sure if I'm supposed to enter the
new static IP anywhere else ... Since Comcast gave us the new static IP
address, I'm assuming the IP address is supposed to be in connection with
our server, right? Or am I suppose to get into my modem settings or
network setting and enter it there too? Is this a firewall problem? Or
should I just wait 48 hours (when I edited the zone file in GoDaddy it
said it would refresh within 1 to 48 hours)?
Am I supposed to re-key and request a new CSR for the security certificate?
Does this problem even have anything to do with the certificate, should I
even touch any settings related to the booking and the certificate in the
server?
I've tried to search, but I guess I don't really know what the problem is
exactly and I haven't messed around with it much (except with the zone
file) since the last time I did I had a HUGE problem that I don't even
remember how ended up making everything work, so please help with any sort
of advice or direction.