SharePoint Online “team news” begins roll out to Office 365 First Release customers

My colleague and I are both testing the new team site 'page' functionality which seemed to roll out to our tenant today. I have hit an issue which my colleague hasn't - when editing the page, if I try to add (or edit) the text web part, all I am able to do is delete it. I am unable to create any text (the text editor bar doesn't appear) and if I try to edit the page where a part with existing text is present, the text disappears (nothing is displayed and I only get the trash can icon to delete the web part). Any idea what could be causing this issue?  

<button type="button" aria-pressed="false" class="ToolbarButton ToolbarSubmenu-displayButton" title="Normal text" tabindex="0" data-automation-id="displayButton" data-reactid=".2.1:$b56b980d-2631-4488-ae97-ec2b5cf2101d.0.0.0.1.0.$format.$displayButton"><i class="" data-reactid=".2.1:$b56b980d-2631-4488-ae97-ec2b5cf2101d.0.0.0.1.0.$format.$displayButton.0"></i><span data-reactid=".2.1:$b56b980d-2631-4488-ae97-ec2b5cf2101d.0.0.0.1.0.$format.$displayButton.1">Normal text</span></button>