During the build of your example cl_dram_hbm_dma, I saw the following output.
WARNING: [Route 35-328] Router estimated timing not met.
Resolution: For a complete and accurate timing signoff, report_timing_summary must be run after route_design. Alternatively, route_design can be run with the -timing_summary option to enable a complete timing signoff at the end of route_design.
Phase 25 Post Router Timing | Checksum: 208b13fd5
And yet I do not find a .VIOLATED file.
$ pwd
/home/ubuntu/aws-fpga
$ find . -iname "*.VIOLATED"
So does that mean that the timing was met despite the warning in the output? I would call this confusing at best.