Here is the response from A2 Hosting, may be that helps to find a solution for this
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We are so sorry to see that the issue still persists, we went and perform the steps directly from the plugin and we received the same issue as well, we checked the PHP settings and the issue still persists, we disabled the a2 optimized plugin and the w3 cached as well and the same issue.
Everything indicates that the issue is coming from the plugin itself, we will recommend you to check with the developer of the plugin what might be the issue since from the hosting side everything is fine.
If you have any further questions or concerns please let us know.
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