I was also experiencing BSOD (Storport.sys , DRIVER NOT EQUAL OR LESS) when trying to upgrade my Windows 10 1903 to 2004. As well as to 20H2.
I also have LSI MegaRAID card installed (ASUS Pike 2208, which is effectively the same as LSI MegaRAID 9265-8i; Firmware Package Version 23.16.0-0021; Driver Version 6.714.05.00).
Upgrading LSI card driver to 6.714.18.0 changed nothing by itself - the next installation attempt failed as well.
But after I ran "Disk cleanup" with admin permissions (this removed "$WINDOWS.~BT" and etc), the next 20H2 upgrade attempt was successful.
Thus, @Dale Kudusi is probably right about updating the driver, but the link he provided does no make sense (points to Version 6.504.5.0, A01 , which is very old). The correct firmware download link is this, it provides Version 06.714.18.00.
PS Here's another my post with effectively the same info.