I just tried this using Max 21 and my 2080ti using driver 27.21.14.6647 (probably needs updating but no issues so have not yet), on a default 4x4 plane, as yours, 4700x3600 and although it does display the 'unsupported' message it will in fact render just fine.
Maybe something there will help troubleshoot or be helpful.
Maybe something there will help troubleshoot or be helpful.
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