Symptoms:

   Recovery volume size doesn't match  

Cause:

The problem is with the system reserved disk.

In the protected side is the original size (e.g. 50 MB)

And in the recovery side is another size (e.g. 4 MB)
     

Solution:

There is a known Hyper-V issue that disks size of the protected VM MUST be in Whole value without decimal (e.g. 1 GB and not 0.11 GB). Once the customer resizes the disks to Whole value the issue resolved.