Scan not starting, Litespeed server

Hey – I’ve got an issue on one site, and one site only with Wordfence. Its the scan which doesn’t work, eveything else is fine.

I’m running WP 4.7.3, Wordfence 6.3.6 & php 5.6.20

I’ve added all the rules outlined on this page and also added this:

<IfModule mod_security.c>
SecFilterEngine Off
SecFilterScanPOST Off
</IfModule>

I’ve ticked in Diagnostics:
Enable debugging mode (increases database load)
Start all scans remotely

Debug output:
Apr 13 11:59:13] Entering start scan routine
[Apr 13 11:59:13] Got value from wf config maxExecutionTime: 256
[Apr 13 11:59:13] getMaxExecutionTime() returning config value: 256
[Apr 13 11:59:13] Starting cron via proxy at URL http://noc1.wordfence.com/scanp/www.domain.com/wp-admin/admin-ajax.php?action=wordfence_doScan&isFork=0&cronKey=123rty969b089b986545a8b
[Apr 13 11:59:16] Scan process ended after forking.

With console open I get no errors – this is the response to /admin-ajax.php
{“ok”:1,”items”:[],”currentScanID”:””,”signatureUpdateTime”:false,”nonce”:”64ce905d76″}

/admin-ajax.php also shows a ‘0’ if accessed directly

Any ideas?