I have 200 metres of zoysia platinum grass that is now 12 months old. Half is under shade of tall trees the other half in sunlight. I had curl grub after 4 months which was treated and cured. Now in winter the grass is brown almost completely both in shade and sun, it is kept watered but not too much, and it is also starting to be able to lift up in sections like lifting a blanket.... I have feed the lawn every 2 to 3 months with slow release fertiliser supposedly for this grass type.... It looks dead but may be dormant however I am concerned due to the ability to lift pieces up anywhere through the lawn...
Zoysia Grass Problem
Certified GKH Gardening Expert
Grubs can damage and kill Zoysia grass. You should not be able to 'lift' the sod, as it should be well rooted by now. If the sod has not rooted, it likely has died off.
These links will help you with care and assessment.