ISO Boot not working- 2011 IMac using UEFI

[Jack1221]

When running UEFI boot on a 2011 iMac the boot into the ventoy menu works fine, but when an ISO is selected the screen goes black and does not respond.  I have tried secure boot mode with the error secure boot platform not found (error 14) when selecting an ISO.  I check-summed the ISO's, so I believe the only issue has to do with either the Mac boot configuration or the fact that rEFInd is installed on my computer, although I bypassed it when booting ventoy for no new results.  Is mac usage known to be a problem? Many threads and the github issues show complaints about iMac issues?  Anyway, if you know of a way to fix issues booting using 2011 iMac please do tell.