Bad News

Do you have any javascript errors shown in the javascript console?

I’ll have to check that. Can it be done in a browser?

Yes, you can get the developer tools your browser has. https://debugbrowser.com/ has a good overview of each browser and how to access that.

Thank you, Jose. I had a look at each file, but unfortunately, I don’t know what to look for. I suspect however that there is a conflict between the plugin and the WP core. Sorry I couldn’t really help in the matter.

You dont need to inspect all files to find errors. You should take a look in the developer tools, there is a console. If there is a javascript error, then this will be printed there. This you could paste here, perhaps we can see something.

Sorry, but that’s a bit beyond me.

And then I look…

And after looking I’m thinking that there are things in the plugin as a whole that a conflicting with the WP core. Try writing the plugin anew.

Can you give some error messages from the console? We use it in different installations without any problems now. Are you sure its coming from the plugin?

I can’t, I don’t know how. All I can advise is that you go through your code thoroughly and take out anything that looks bad. I’m going to try it with just your plugin active and see what happens then.