Avoid SMR drives. Limit the use of refurbished drives, no more than 1 less of your fault tolerance, but try to keep it to just 1. You can guess the life remaining based on the hours reported from SMART.

Try connecting it directly, using SATA, to a machine running a flavor of linux, like ubuntu. I have found that they are much more forgiving. You might try a different USB adapter, but that just adds more to the troubleshoot chain.