WL1837MOD: Measuring Tx Power from MCS9-15 at 40 MHz MIMO

I'm trying to measure the Tx Power at 40 MHz in Channel 3 and 5. I'm able to measure from MCS0-MCS7 easily using the example script below:

calibrator wlan0 wl18xx_plt stop_tx
calibrator wlan0 wl18xx_plt tune_channel 5 0 2
calibrator wlan0 wl18xx_plt set_tx_power 20000 0 0 3 1 0 0 1 0 0 0 0
calibrator wlan0 wl18xx_plt start_tx 500 19 500 0 0 1 0 0 \
ea:2e:9c:d5:35:f2 00:24:9B:6A:8B:87 1

This picture above corresponds to the command used at MCS7 rate

Now when I try to measure from MCS9 (which is 21) using that script in MIMO, I'm not seeing any sort of frequency or a graph from the litepoint setup using the calibrator tool. I'm wondering if there is a script that works for 40 MHz MIMO

Thanks