Steps to reproduce the issue

Backend:

1. Go to Content->Fields and create a field with type: Checkboxes.
2. Assign it to a Field Group and a Category.
3. Among Checkbox Values, add Name: '£30,000+', Value: '20000'
4. Publish field.
5. Go to Content->Articles and create an article and choose the same Category that the Field is assigned to.

Expected result

On Article edit page the Field Group tab should come up with the Field inside that we set up above.

Actual result

On Article edit page the Field Group tab is not showing.

If at this stage you go and remove the £ (pound) sign from the Checkbox Values Name field then go back to the article, the Field Group tab shows correctly.

System information (as much as possible)

Database Version 5.7.14
Database Collation utf8_general_ci
Database Connection Collation utf8mb4_general_ci
PHP Version 5.6.25
Web Server Apache/2.4.23 (Win64) PHP/5.6.25
WebServer to PHP Interface apache2handler
Joomla! Version Joomla! 3.7.0 Stable [ Amani ] 25-April-2017 15:36 GMT
Joomla! Platform Version Joomla Platform 13.1.0 Stable [ Curiosity ] 24-Apr-2013 00:00 GMT
User Agent Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.96 Safari/537.36

Additional comments