Autoptimize ‘suspicious javascript code’ warning

I recently installed Autoptimize on the website for my club. I’ve enabled the Javascript optimizer and not too long ago, we started having issues with MS browsers blocking the site, reporting it as unsafe. I’ve done a scan on pcrisk.com and their scanner suggested there are 3 files created by your plugin causing the issue, like so:

/wp-content/cache/autoptimize/js/autoptimize_a983704174d6e18552569bd9419dde0e.js
Severity:	Suspicious
Reason:	Detected suspicious JavaScript code
Details:	Detected encoded JavaScript code commonly used to hide suspicious behaviour.
Offset:	24
Threat dump:	View code
File size[byte]:	231136
File type:	ASCII
MD5:	88E2B2346CFD5D3DBC2AF672EE3EAA3A
Scan duration[sec]:	20.855

/wp-content/cache/autoptimize/js/autoptimize_532a2cc8a7919512c333b099908e5de6.js
Severity:	Suspicious
Reason:	Detected suspicious JavaScript code
Details:	Detected encoded JavaScript code commonly used to hide suspicious behaviour.
Offset:	24
Threat dump:	View code
File size[byte]:	267065
File type:	ASCII
MD5:	06F7BD570C693AE94DFF7C6BC337B90F
Scan duration[sec]:	21.505

/wp-content/cache/autoptimize/js/autoptimize_925a2c108644648ff10d6082ecfc7e33.js
Severity:	Suspicious
Reason:	Detected suspicious JavaScript code
Details:	Detected encoded JavaScript code commonly used to hide suspicious behaviour.
Offset:	24
Threat dump:	View code
File size[byte]:	350218
File type:	ASCII
MD5:	4730BD75ED744E69D1B751C85AC9BE12
Scan duration[sec]:	24.124

I’ve not had this issue with any other website I’ve built, which mostly use your plugin for optimisation purposes.

Please can you help me to understand what this error is, why it is happening and what I can do to sort it?

Thanks in advance.

Best wishes,

James