Hi! I have just upgraded to Joomla 3.7.4 with JEvents 3.4.39 - this is when issue started.
On front end editing you see a pencil (edit icon). This icon used to enable editing of the event. Now when clicking the edit pencil icon, the options pop up for a second and then disappears. I have changed template back to default and it works well as before upgrade. I have contacted the template developer and they aren't willing to help here. Please see if there is something you can do to help.
Thank you!