Just checking the error log for Cupcake’s issues (see MSB), I noticed these:
2019-05-15 10:08:58 ERROR - Web client error: a glimmer transaction was begun, but one already exists. You may have a nested transaction : undefined.
2019-05-15 10:08:58 ERROR - Web client error: Object doesn't support property or method 'includes' : undefined.
No one (other than Cupcake) has reported any errors, and everything is working fine for me.