Congress should not pass laws that apply to others and not themselves, or that apply to themselves and not to others. I thinker most citizens can agree with this.
The reality is this: either Congress isn’t doing this, and there is no problem. Passing this will not change anything. Or Congress is doing this, possibly frequently, and there is no way they will ever pass this amendment, so it will only ever happen is through new amendments passed in an Article V Convention and ratified by the states.
Congress may pass no law that does not apply equally to them and to all United States citizens. They may not be exempted from any law, save only that they may refuse to provide information or access if doing so could be detrimental to national security.