It looks like, that is some sort of shortcode argument leftover or something very similar to that. The plugin tries to extract those shortcodes and remove them for better performance, but I guess the content of this shortcode is encoded in some way, so it should be rather exectuted.
Try changing this option to ‘Execute them’: https://i.imgur.com/kG5vSCF.png
It should very likely solve the issue, by executing the shortcodes and getting their output.Best,
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