Hi,
Looking at
Cisco SD-Access 1.3.x Hardware and Software Compatibility Matrix
https://www.cisco.com/c/en/us/solutions/enterprise-networks/software-defined-access/compatibility-matrix.html
Recommended ISE version for DNAC 1.3.1.5 is 2.4 patch 11
Looking at Compatibility Matrix (An interactive tool to determine product and software feature compatibility.)
https://content.cisco.com/compatibilitymatrix.html
Recommended ISE version for DNAC 1.3.1 is 2.6 patch 1
We are probably in transition but this difference could cause confusion
Thanks
Fab