Hi,
It is hard to say what the issue is without seeing it. If you are running Filter Bar 3.7 with Events Calendar 3.9 that could be the issue as those versions are not compatible. (although it is possible they might work together we do not test for that).
If you run 3.7 for all versions of the Events Calendar Plugins that might resolve the issue.
You could also follow our testing for conflicts guide:
Testing Conflicts With Themes and Other Plugins
And see if your theme or another plugin is causing a conflict.
Unfortunately, that is about all the help I can suggest on the Pre-Sales Forum.
Cheers