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But according to your decription, this issue is more related to flow, please check whether the known issues and limitations is helpful.
Such as the maximum archive size for Extract archive to folder action is 50 MB and 100 files inside.
To help you better, it's recommended to post a new thread on Microsoft Power Automate community. Thanks for your understandings.
Besides, I find 2 similar threads, you can have a look.
Convert to PDF Not Working
400 Error Conversion to PDF not supported
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