Should my website be accessible by IP?

[WAWKA]

I have been doing some digging in to this today essentially triggered off by looking at the secure certificate on my site and comparing it to others as i have been seeing some security warnings on a random basis.  I noticed that on all instances none of the other sites IP addresses re-direct to the website, whereas on my site it does.

is re-directing the IP address to the website a big no-no?

[PShez]

also going to https://casecurity.ssllabs.com/index.html and entering "example.com" or "www.example.com" shows two different certificates.

the "example.com" certificate comes up as not trusted and when pasting the ip address into the browser it redirects through to the website.

www.example.com certificate comes up as trusted, however when pasting the the ip address it takes me through to a page with the message "your connection is not private" and when clicking the continue anyway link, it takes me through to an unsecure IIS page?

is this a problem? or is this a non-issue?