Default [Q] Couldn't open ADB Shell

In recovery mode, I couldn't access shell window by using adb shell command. (Referring to the attached pic)

The device has already be rooted and OS run very well.

I also checked the hierarchy of the system, system/bin/sh does exist.

So what's wrong with it, any advice welcome!

BTW, this adb file works fine with my another mobile featured with Qualcomm CPU, hence is adb file dependent on type of CPU?
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