Post Indexer and Global Search

The post indexer on our multisite stopped working around Aug. 11. It would say it was indexing but no articles would be updated. As of yesterday, the most recent posts indexed were Aug. 10 posts.

Thinking maybe there was a plugin hiccup, I clicked the rebuild index button...
It wiped the existing index put the 60 sites in queue and nothing...

WP Engine has verified that alt chron is running. It appears that the script is exceeding timeout limits of 60 seconds. So the question is - can we batch process the full network reindexing so that it doesn't timeout? Prior to August, it had been working fine with no issues.

We're at a standstill on how to get the indexer back up and running so that global search can work again.

Various troubleshooting steps we've taken:
- Purged server cache
- Turned off CDN
- Made sure all sites were listed in the config file.
- Reset file permissions
- Am now getting to the point of uninstalling and reinstalling the plugins