Why is there a difference between zpower on android tablet versus pc?

@Paul_Allen Why is there a difference between zpower on android tablet versus pc?

Doing 100 rpm with same cadence and speed sensors it determines zpower as 268 watts on Android Samsung S6 Tablet on ant+. Same rpm on ant+ for zwift on Windows 10 pc gets calculated at 138 watts for the same user.

Is there a reason for this?

Both connect to the same garmin speed sensor over ant+ so was expecting exactly same values. Don’t understand why it would be different.

Has anyone seen this before?
I suspect it will be fine when connected to a power meter.