Hi
I did send your support team an email about this issue at the same time as posting here.
I have worked around the issue by adding the JS snippet provided in the Sonetel portal to the footer on my website. This works well.
Is there any advantage (eg further customisation) to using the WP plugin?
If not then I will uninstall it and continue to use the JS snippet.
At any rate you may want to investigate this issue from a technical point of view.