HA sync not happened

Have you tried to force config sync?

https://support.f5.com/csp/article/K13920

https://support.f5.com/csp/article/K13887

Also have you reviewed this article and followed for issues like ntp, device trust etc. ?

https://support.f5.com/csp/article/K13946#cso

All parameters are the same and there is no issue.

Getting same issue as this "device-group-failover-2cd1d1b1ad04" group is not in sync.

Have you also done tcpdump on two devices to see that config sync request packet is send by the active device and recieved by the standby checked the iQuery part of the article and used iqdump to verify the iquery communication during sync?

https://support.f5.com/csp/article/K13690

https://support.f5.com/csp/article/K411

https://support.f5.com/csp/article/K13637

Also see this as this is why I proposed full force sync as with big configs the incremental sync may fail because of the limit 1024 :

https://support.f5.com/csp/article/K10762232

https://devcentral.f5.com/s/question/0D51T00006uM4MK/advantange-and-disadvantage-of-full-sync-and-an-incremental-sync

Check the /var/log/ltm logs during the sync operation and you can also add them here and also a screenshot with "advanced" view as your previous screenshot is "Basic"

cool, I will do above steps and share the output with you.

Thanks for the support.

got stuck once in a similar way....later came to find out I had been using packet filtering ....

its worked on BIGIP-12.1.2.0.0.249.ALL-scsi version;

Thanks guys for support