Moving back from SSD to SD Card

RaspberryPi 4 - 4GB
I have moved the root directory from OH3 to a SSD. Works so far but little slow.

When i boot without SSD Drive and with OH3 SD Card inserted. The system doesnt start.

How is it possible to switch back to SD Card?

Performane Problem solved. Using of USB 2 port is much more faster!