Male female power cable keeps on coming loose while riding ebike. Help?

cross-posted from: https://lemmy.perthchat.org/post/321128

I have tried: taping them together, hot glueing them together and ziptying it right to the frame to prevent jiggle.

All have failed.

Right now, when I reconnect them and apply pressure, I can't even get the engine to turn on anymore. But the speedometer still works and that signal is sent through the engine cable too.

Recently, sometimes the engine rear wheel barely rolls when I roll the bike backwards.

There are no ebike repair stores in my city.