I'm having a similar issue...installed the 7/31/20 eeprom update, created a fresh 9.2.5 install on my SSD...it will eventually boot, but only after MANY minutes and a huge list of errors...a reboot never finished after 2 hours...just a massive list of errors.
EDIT: using this page STICKY: If you have a Raspberry Pi 4 and are getting bad speeds transferring data to/from USB3.0 SSDs, read this - Raspberry Pi Forums I was able to set my USB->SATA adapter as mass storage instead of SCSI...this fixed the issue immediately. Now I have a new issue, which is probably unrelated...CEC control is no longer functioning.