Idp version for Node0 and Node1 are not in sync. While Node0 has been updated to the new version (3764), Node1 is still on version 3762.

{primary:node0}
root> request security idp security-package install status 
node0:
--------------------------------------------------------------------------
Done;Attack DB update : not performed
due to the same version between downloaded one and installed one.
Updating control and data-plane with new detector : not performed
due to the same detector version between downloaded and installed one.

node1:
--------------------------------------------------------------------------
Done;AI installation failed! Attack DB update failed!
Install from IDP failed. Checksum validation failed for downloaded files.

{primary:node0}
root> show security idp security-package-version 
node0:
--------------------------------------------------------------------------

Attack database version:3764(Thu Dec 12 14:22:56 2024 UTC)
Detector version :12.6.130240709
Policy template version :N/A
Rollback Attack database version :3763(Tue Dec 10 14:20:27 2024 UTC)
Rollback Detector version : 12.6.130240709

node1:
--------------------------------------------------------------------------

Attack database version:3762(Thu Dec 5 16:34:23 2024 UTC)
Detector version :12.6.130240709
Policy template version :N/A
Rollback Attack database version :3761(Tue Dec 3 15:46:45 2024 UTC)
Rollback Detector version : 12.6.130240709

Do a full update for IDP and check if it helps. 

srx> request security idp security-package download full-update 

If this do not help, then, remove the IDP DB from node1 and re-install the IDP. 

Steps are as follows:

To delete IDP:

• Enter configuration mode and disable the IDP process.

 srx# set system processes idp-policy disable

srx# deactivate security idp

srx# commit

• In order to rebuild the IDP directory, we should first delete the directory from shell (as root).

srx> start shell

% rm -r /var/db/idpd

• After verifying that the IDP directory is deleted, reboot the device

% cli

srx> request system reboot

• The reboot of the device will automatically remake the IDP folder/directory.

>Once reboot is done, re-install the IDP. 

If issue persist even after the above, please contact JTAC.