Having the same issue myself. I am only able to connect either my cadence or speed sensor via Bluetooth, not both at the same time. They are the same make (not Wahoo though but work the same way) and when I pair the second I end up with ‘no signal’ coming from one of them. Bluetooth names show as BK6 C-574389 43 and BK6 S-574362 139. Maybe the app is not reading reading enough of the name (or only reads up to the space before thinking they are the same device). Sensors work together with no issue on PC using BLE and compaion app.
Also want to reply about the earlier comment about a phone only having one Bluetooth radio in a phone… You only need one Bluetooth receiver in a decice as it can maintain nearly unlimited connections simultaneously with no issues.