I've got a Merach TT smart trainer that's easily picked up by most cycling apps (Zwift, MyWhoosh, etc.) but not my 840.
I've tried pairing it through the sensor menu and the training > smart trainer menu, and the 840 doesn't even see it.
The trainer doesn't use ANT+ but Bluetooth, and I've made sure to unpair it from all apps before trying, but nothing.
Any ideas?