Yet more Apple Core Rot, it seems.
... We determined that the kernel panic occurs when the 2019 Mac Pro sleeps. More importantly, we figured out that the problem only occurs when the OWC Accelsior 4M2 is installed in slots 4 or 5 and only if those slots are configured to use pool B of the PCIe lanes (see below). If OWC Accelsior 4M2 is in any other slot, or if it is configured to use pool A, no kernel panics occur.
The teams also found other cards, which, when installed, result in a kernel panic. One example is the Highpoint SSD7101A.
Getting Help From Our Chip Supplier
We then contacted our PCIe chip supplier in Taiwan to get help determining why macOS thought there was an error on the PCIe bus. Their engineers analyzed the signals on the PCIe bus and told us that macOS was mistakenly indicating that there is an error when, in fact, all the signals were correct.
Apple Starts Investigating
We have since reported this problem to Apple and are working with them to develop a solution. Like the problem we discovered recently — where a Mac hangs while transferring large files — I am confident that they will develop a quick and reliable fix for this problem.