I also have some Martin Jerry smart plugs that I loaded Tasmota on. One problem with these is they display as OFF in the Tasmota software when they are on. I removed entries from GPI04 and GPI05 to get rid of two extra buttons that were displayed in the GUI. The button on the side of the plug works but doesn’t light up right now.
For the plugs that I had, the relay needed to be changed otherwise off was on and on was off. So D6 change 29 to 21 and it works as expected.