My team has noticed a few configurations for which the site definition process was frustrated because of what appears to be browser specific bugs. By switching from one browser/computer combination to another, the confusing behavior disappeared. I don't know where bug reports should go, but these are what we saw. My goal here is not to be hyper-critical but to try to help.
In each case, it was either me or one of the grad students that work in or for my solar laboratory who received the link provided in the Share It pop up:
These are the site misbehaviors we witnessed and I confirmed.
On Firefox 61.0.1 (64-bit) running on Fedora 28, the ability to add an example question did not lead to the form to submit the example title and body. Clicking on it did nothing. When the grad student switched to Chrome 68.0.3440.84 (64-bit), the exact same sequence of browser operations produced the expected form and she was able to submit a question.
The same browser/computer combination above did not allow a Stack Exchange log-in for me. The spinner (the kind that usually indicates the page is waiting for an AJAX request to reply) hung. The input fields for the account and password never appeared. I tried twice with Firefox 61.0.1 and upon switching to Chrome 68.0.3440.84, the input form appeared as expected.
Another student using Safari on iPhone (HTTP_USER_AGENT of ... iPhone OS 11_3 ... AppleWebKit/605.1.15 ... Mobile/15E302 ...) found that selecting Follow It changed the text to Unfollow as expected, but she didn't appear in the list of people following when I refreshed in my side. We tried it three times and waited in case there was a process that had to finish on the server. No luck. When she moved to her Windows 10.0 laptop and used IE she was able to Unfollow and re-Follow-It and when I refreshed two seconds later, she appeared as a follower.
Can those bugs be fixed? My suggestion as a professional systems architect with web site usability experience is that SE do some multiple browser testing with Firefox, Safari, and other common mobile browsers to ensure that community growth is not frustrated because of bugs.