This isthe statement from the RSEvents Developers Support: NOTE: The Admin Button and the Event Buttons should offer drop down options

Although the component provides an option to disable Bootstrap, leaving this handling by the template, if the template doesn't provide some compatibility declarations for the standard Joomla! Bootstrap framework, this will not help.

You can easily test if RSEvents!Pro works or not, by temporarily switching to a standard Joomla! template like Protostar and I'm fairly certain this will work since if you access the following direct URL that doesn't load your template, as you can see this is working:

https://communitymusicmatters.com/find-live-music/event/472-brent-butt?tmpl=system

In case you're using template overrides for RSEvents!Pro, have them temporarily removed while testing this.

Please directly contact your template developers on this matter to provide you with assistance.