I reviewed this problem and couldn’t reproduce it.
Actually i am using WordPress 4.9.4 and speed-contact bar version 6.0.
As written in the other topic the person used WordPress 4.8.1.
Maybe there was a problem with the antispambot function in an old wordpress version.
It works without problems on chrome/firefox/ie.
Personally i would suggest readding the antispambot function as mentioned in my first post because a clear email-adress is easy to crawl for harvesters.