I have bougth 10 MK01 blind Tasmota modules, that looks fantastic. I have been programing and testing and seems there is a problem with the cabling of switches. I am using the normal wall switches but connected to the module instead of the blind motor.
I had to install 1M resistors in the "S1" and "S2" inputs to pull down to "N"becasue the floating voltage was not allowing the switches work well.
With the resistors, the devices are working well. But the solution is not great, I rather prefer to see the resistors inside the device in the PCB.