Question about contract agency fee

Background: My agency has been submitting me for jobs, but I haven't booked anything through the agency. I have been booking jobs on my own through various postings. My last job, I listed my agency on the paperwork, payment was sent directly to my agency, and they are asking for 20%. The way I interpret the contract the 20% only goes to them if they book the job for me. Wondering if this is standard practice. Also, is it a bad sign I haven't booked any work through the agency. For context, and am an over 50 model in the classic section doing lifestyle modeling.

I hereby agree to pay XXXXXXXXXX Inc., 20% commission on ALL talent fees received by me as a result of a booking through the agency. I agree that all talent fees earned by me shall be paid directly to the agency. This agreement also encompasses residuals and/or other fees, payments made payable to me. Should payment be forwarded directly to me by the client, I agree to reimburse the agency it’s 20% commission immediately.
20% is the commission payable to the agency by the model or talent for a Non-Union job. . This is an Exclusive contract/agreement between the talent listed above and XXXXXXXXXI hereby give permission to XXXXXXXXXXX. to negotiate with the client in my best interest. I am aware this is an exclusive contract between myself and XXXXX Agency, Inc. and will not sign with another modeling/talent agency within a 150-mile radius.