Hi @aliceo ,
Could you please share a bit more about the second column that you mentioned within your Data Table control?
Could you please share a bit more about your data source? Is it a SP list? Is the second column that you mentioned is the 'Link to Item' column?
Based on the issue that you mentioned, I think you have something misunderstanding on the "Is Hyperlink" property of columns of the Data Table control.
The "Is Hyperlink" property of columns of Data Table control would recognize if a column in your Data Table is a Hyperlink column. When you set the "Is Hyperlink" property of columns of Data Table control to true, it just recognize this column as Hyperlink, but not have Hyperlink functionality (click it to navigate to open corresponding web page).
As an alternative solution, I think the Launch function could achieve your needs. I have made a test on my side, please take a try with the following workaround:
Set the OnSelect property of the second column in the Data Table control to following:
Launch(DataTable1.Selected.'Link to item')
Note: The data source in my Data Table is a SP list.
On your side, you should type:
Launch(DataTable1.Selected.'Your Second Column')
More details about the Launch function in PowerApps, please check the following article:
Lauch function
Best regards,