Appian application using Selenium/ Java - Facing Issue with Drop down value selection and Date Selector [Picker]

I am facing issue in identifying the objects using Selenium/Java on sample Appian application available at Community edition site as below:

Similar issue I am facing in working project screens for one of the clients.

1. Multiple - Dropdown: The dropdown values are not defined as Static. The <div> id has changed whenever page is getting reloaded.

2. Date Selector: The <div> id has changed whenever page is getting reloaded. sendKeys () method is also not working since the field was changing dynamically.