This is fairly common. You’re average weekly wage is based on what your earned on the job where you got hurt. This is true even if you’re disabled from the other job. While that is difficult for you as a practical matter it’s only fair that your employer’s liability be limited to taking care of you on this job. The good thing is that you are entitled to make money on the other job without workers’ compensation taking a credit for it unless you expand your hours or are making more money on the other job now that you’ve got more time for it. This is always a tricky situation and really requires a good conversation with an attorney.