2018 WRX Stock front O2 sensor range

Does anyone know what the range is on the stock front O2 sensor? during a full 3rd gear pull, above 3800rpm, the sensor flatlines at 10.14:1 while the commanded fuel final is roughly 10.72. I'm concerned that the real AFR is richer than the reading. Any tips are appreciated, cheers

Hello i cant find any info online to confirm but from memory they go to about 10 flat

curiosity why ar you running so rich ?

Turns out that my MAF sensor scaling was off although now that I'm running the commanded AFR of between 11 and 10.7 on WOT, I'm getting some serious knock events and drops in the DAM with the base ignition timing that is on the latest Cobb base map, version 3.60

Be mindful of the accuracy of the front sensor. Yes, it's a wideband sensor, however Subaru only intend it to be used at or close to stoich. In the worked example we've just shot on a V11 Sti the factory sensor reads about 0.2 richer than a proper wideband.