Hi there - I'm also having this problem but do have a workaround.
When I create a site abd click OK I then manually type the link of the site that should have been created... eg ww.worksharepoint.com/sites/newsite and once this page opens it automatically redirects to the page where I normally select the site template.
After that the rest seems to work fine apart from the population of the Site Listing. I have to manually enter all the new site details into this page via the Edit in Datasheet option. Then the new site is listed on the Site Listing.
Obviously it's a bit of a pain, so I'm also wondering if anyone out there has a fix for this? Being kinda new to all this I can't say what's going wrong but it seems to be at the point when you click OK that it doesn't automatically add all the new site data onto the main Site Listing and also doesn't pop up a new window automatically with the new site on it. Probably doesn't help but I thought I'd mention it.
Ratty (not a looong time reader but a first time poster for sure)