Powering Tinkerboard S via GPIO

I would like to try to power the TinkerboardS (TBS) over the GPIO pins. However, the TBS doesn’t boot. Powering over micro USB is ok. On the Armbian forum I found a thread that rootcause could be a bug in u-boot 2.0.4 on Tinker OS. In version 2.0.5 the issue is solved. Does anyone know which version of u-boot is used in the Tinker OS used in Volumio?