Reindexing was in progress on master node but after rebooting cluster it is halted

Reindexing was in progress on master node but after rebooting cluster it is halted.

We have 3 master nodes and multiple data nodes and we have rebooted all one by one. Everything is up and running but reindexing is not resumed. could anyone please let us know how to fix it?

What version are you running?
How did you start the reindex process?

Version:- 7.9.3
I used normal reindexing command but that index consist of data in GB's. Also we are using hot/cold/warm architecture. And just for you info we have 17 nodes cluster. 3 Master node, 3 Hot node, 5 cold node & 6 warm node.