So the status of your Hyper-V replica shows that replication health is critical and if I click resume replication, it says replicating changes >> and after a few moments >> failed.
There is no other option to fix this issue. Try these steps:
(I use Hyper-V manager for this procedure)
1. From the primary site, remove replication using “remove replication” option.
This will leave the replica VM on the DR site intact.
2. Now, on the DR site, remove replication.
If you look at this replica VM inside VMM, you will see that now it has become a regular VM. It looks like a regular server instead of a server with a shadow behind it. (you may have to refresh VMM)
3. On the primary site, right click on the VM and choose enable replication.
4. Go through the wizard, (next-next) until you come to the “Choose initial replication” page. On that page, choose the option “Use an existing virtual machine on the replica server…”
5. Click finish and it shows “sending initial replica (progress percentage).
Don’t worry, it is not really all the data, it is synchronizing with the data already there at the DR site.
That’s it folks! I hope it helps someone.