Chat not working – Plugin contention

The chat function is not working.
It is ok when logged in, but for logged-out users it is not displaying on the screen.
While inspecting the issue, I receive the following error message:
‘Uncaught ReferenceError: njtWhatsApp is not defined.’
at nta-js-popup.min.js?ver=3.7.3:1:13
at nta-js-popup.min.js?ver=3.7.3:1:673

Essential versions
WordPress version 6.9.4 (untested with this plugin)
Active theme: Page builder Framework (2.11.9) built using Beaver Builder – Standard Version (2.10.1.5)
Current plugin: WP Chat App (version 3.7.3)
PHP version 8.2.30 (Have changed version up and down with no positive results for this issue)

After deactivating all plugins (apart from essentials) and then reactivating them one by one, the culprit was ‘Speed Optimiser’ from SiteGround.
Changing the setting in this plugin to disable ‘Defer Render-blocking JavaScript’ resolved this matter.

If there is a workaround to resolve this issue while keeping ‘Defer Render-blocking JavaScript’ activated, it would be great.
Not a deal-breaker, tho.

Regards,
Tork

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