You are using a very old version of the properties panel. We are currently at bpmn-js-properties-panel@4.0.1 and @bpmn-io/properties-panel@3.2.0. You can check for outdated versions using npm outdated.
Updating to the latest versions should resolve this issue.
Okay, if this did not fix it, please share a CodeSandbox that reproduces your issue in a way that we can inspect it. It is hard to root-cause an issue with only a screenshot