Short answer: It's not going to work.
Long answer: I have a Mi4c and Jodel stopped working as well.
I got in contact with the devs and they can't help. There are 3 xiaomi devices which have problems with jodel. Without a device to test, they can't provide a fix. (They are in Berlin which is halfway across germany for me...)
And upgrading to Android 7 didn't change a thing.
You can try to get some versions from apkmirror or such, and try to install them, but for me none worked. The only "workaround" is using version 3.1.40, the last one with the last UI, with that I can atleast read, but can't reply or comment...
So yeah, it's not working...