Robots.txt tester shows "!-- WP Optimize page cache" error

Hi, everyone, I ran a robotx.txt test on GSC and it shows the following in the last two lines:

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Disallow: /wp-content/uploads/wpo-plugins-tables-list.json (not sure this is even relevant but gonna paste here anyway)

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<!-- WP Optimize page cache - https://getwpo.com - page NOT cached because: Output is too small (less than 255 bytes) to be worth caching -->

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My questions are: how serious is it? And how can I solve it?