Unable to run scan on website – Scan process ended after forking.

I have a problem where wordfence isn’t running scans on my site. I’ve tried switching off all plugins and clearing the cache but the wordfence scanner is unable to start and keeps running these messages in the log:

Got value from wf config maxExecutionTime: 20
[Apr 16 13:01:32] getMaxExecutionTime() returning config value: 20
[Apr 16 13:01:32] Starting cron via proxy at URL https://noc1.wordfence.com/scanp/www.kiickit.com/wp-admin/admin-ajax.php?action=wordfence_doScan&isFork=0&scanMode=standard&cronKey=0cc9f3df343670b1213e2724f7afe2c1&k=f9847b956bd7ad8b49baade9de20e973223fe4799106bf13a7844877cd187a2fb3330e307bfe680bbc0cdce34f49a898011309874dc34bf487e0ff20397530054ccd5f4f7291c7227f006f39bc61eae4&ssl=1&signature=34cfcb4780a9792395423af6471569fe0c50f813bf53b5d3aa846762a4e3a299
[Apr 16 13:01:33] Scan process ended after forking.

I’ve gone through all similar posts in this forum and none of the solutions have worked so far. Does anyone know how to resolve this problem?

Thanks,