Hi - I hope that you are Doing good !!

To refresh information from a CSV, re-upload the file.
To link more than one data set, click on the drop-down menu above the imported sheet in the Data Panel, and select “Add New Dataset.” You can also use this panel to toggle between, refresh, replace, or delete linked data sets.

KIndly look in to the below blog:

https://www.lucidchart.com/blog/make-your-diagrams-dynamic-with-data-linking#:~:text=To%20refresh%20information%20from%20a,or%20delete%20linked%20data%20sets.

Happy to help further !!

Hope this helps

Thank you very much and have a fantastic day!
Warm regards

Thank you Huma,

The  “re-upload”  option  doesn't exist in the menu, I used "replace dataset" instead. after that I had to select “CSV” and not “choose previousely uploaded dataset”.

The data in the shapes did update successfully, unlike when I tried the same procedure with xls files

Thanks and regards.

Hello!  I’m bumping this thread to let you know that we are actively developing an Excel integration with Lucidchart. This feature will allow you to import spreadsheets from Office 365 business accounts, and have 2-way syncing between Lucid and your Excel spreadsheet. 

If you (or anyone reading this) is interested, shoot me a DM. I can get you onboarded to our Excel beta.  We’re actively looking for testers that can provide feedback and feature requests for this new capability.