Hi Robert,
Thanks for contacting syncfusion forum.
We are using Jquery 8.1 version in our source and we have tried your requirement of using both JQueryUIDatePicker and RichTextEditor control in versions specified by you and it works fine in our end. We attached the sample and please try the sample which is available in the following link,
DatePicker-1181882449.zipIf the issue exists still, could you please modify the attached sample and share with us to isolate this issue in our end.
Also, when there are two different versions of jQuery is used conflict may occurs and it can be resolved by using jQuery.conflict() as you specified.
Regards,
Varalakshmi