I have never seen this happen and I am running the most recent versions of both SM plugin and WP core. You are likely experiencing a plugin conflict or something broke in your WP installation (least likely scenario but still possible).
Follow the standard troubleshooting steps to identify the cause (FYI, this applies to all plugin issues, not just sermon manager!)
1) Disable all plugins except Sermon Manager-- is the issue fixed? If yes go to step 2, if no go to step 1.a
1.a) Change your theme to default like twenty fifteen -- is the issue fixed? If yes go to 1.b, if no your WP install is broke--you'll need to start over
1.b) Something in your theme is causing the issue. Contact the company that supports your theme and present the evidence that proves that the theme is at fault. If no such support exists you should switch to a theme that complies with WordPress standards and gives you less trouble.
2) Activate your plugins one by one, checking the status of the issue between every single one...you will eventually discover which plugin is conflicting with SM. You can either choose to (a) dump that other plugin in favor of SM or (b) present the plugin details here so that further assessment can be made.
Please report your findings here so that worthwhile troubleshooting assistance can be offered.