How to change Android system boot slot form A to B

try setting the slots again, without the space between -- It will return fastboot --set-active:a fastboot: unknown option – set-active:a

I choose yes and then get back in recovery with “Active slot: b ” I didn't need to do fastboot —set-active=b So I then relaunch: adb

fastboot change slot Advanced features include Active When placed in an HDMI slot on a television set or computer monitor, the device turns that display into a personal computer

fastboot_ error_ failed to identify current slot slots ourselves using a Fastboot command Changing Android's Active Partition Slot