When adding a hyperlink to send email or task email notification by clicking the add link icon, specifying the URL with Item Url and text as item Title.
This issue is happening with Nintex for office 365.
The href keeps on breaking the html as below to the extend that you wont receive emails.
Href="href"#""
<p>
<span contenteditable="false" data-nintextoken="true" style="display:inline-block;">
<a class="ms-rtestate-write draggableToken" contenteditable="false" href="href=" #"" link="true" onclick="return false;"
reflink="nw-stringbuilder-token-31a5cef8-84a0-4173-bfba-7cd75bf557fd" reftext="nw-stringbuilder-token-c4588aa7-3539-4fc2-82ba-5c7c74edfc91"
spellcheck="false" style="color:blue;cursor:pointer !important;">
<span data-nintextoken="true">Testing</span></a></span>
</p>