Homepage Slider not working with Chat-Widget

Hi in integrated the widget as a sidebar item on two subsites. when activating the plugin my homepage slider will no longer work.
what may be the problem? https://www.itsm-education.de –> that is the slider’s page.
https://www.itsm-education.de/itil –> here is the chat-widget activated

thanks in advance
natascha

https://www.ads-software.com/extend/plugins/flexytalk-widget/