Having had the exact same problem I believe the problem is difficult to solve, hence why this issue still exists 5+ months after it was first reported.
As the issue I believe may be caused by not just the hardware or just the software but a combination of the two…
While switching to ant+ will solve everyones problems as mentioned it would be real nice for all of us who have purchased zwift and these smart trainers, that the device works out of the box (without the need to purchase additional addons like ant+)
To properly troubleshoot the problem I tried the following connection types with Zwift:
-Android Marshmallow phone with the mobile link app will detect all other bluetooth sensors but not the power sensor.
-Android Marshmallow phone with myetrainer app will detect all other bluetooth sensors but not the power sensor. The power sensor is detectable by Ant+ via the android native support however.
-Iphone 4 via bluetooth and the mobile link app the power sensor can be read along with the other sensors.
-Iphone 4 with the myetrainer app via bluetooth the power sensor can be read along with the other sensors.
-An Android marshmallow phone with mobile link app and Ant + connection the sensors connected to the PC via ant+ are working perfectly ( a fix but not the solution! ).
My read of the "Possible’ Cause:
I believe the issue may be because the Android has support for the ant+ standard, whereas this protocol is not supported by iphones. As Ant+ is on by default, the signal from an android device may be able to be being detected by the qubo as the first thing it reads.
I heard a rumour from other users that the Qubo has a firmware issue that it has a tendency to pair to the first wireless protocol it detects and then gets stuck in that mode from then on (ie ignoring the bluetooth signal).
Being that android phone unlike all Iphones support the ant+ protocol, for those users with the mytrainer app installed, if this is used first then the qubo detects the ant+ power signal and then fails to detect the bluetooth signal from then on.
This hardware fault when combined with the use of the zwift mobile link app which can only detect bluetooth signals (on both android and iphones) then of course fails to be able to detect the power signal.
The zwift application fails to pair to the smart trainer via the zwift mobile link, because the qubo is no longer listening for the bluetooth standard to connect too it, which is where all of the non ant+ users are stuck.
Both suppliers are slightly pointing the finger at the other to solve this issue, (This is exactly where my support enquiries were left by both teams)
So I would hope the teams could communicate a bit further on the above and resolve this once and for all on these forums! Thanking you.