What storage controller and backplane did you have on the server? Is it a PERC controller for S140 Software RAID controller. If it is a S140 controller then only SATA drives are supported. Can you check the physical disk status in iDRAC As the status LED is off, it is mostly drive not detected. You can refer below link for drive LED status [URL] 
I have four SAS HDDs inserted into my Dell Poweredge R740 server. All 4 drives got power but when I went to install OS (ubuntu 22.04) it does not detect any drive. Also while I was running the troubleshooter, it could not find any drive as well. Also while I was looking for physical drive properties, none of the 4 HDD drives were detected.  Please note that, after powering up my server, only one of the 2 HDD indicator lights turned on the other remained off (see attached photo) [IMAGE]  Thanks a lot  
SAS HDD not detected on Poweredge r740