Hi Dave, Try setting the shaping to 200mbps and see if that helps. Some modem expects the router to do the shaping or else packet will be dropped. When doing a throughput test from the LAN, that device might try to generate more than 200mbps and when the modem is only capable of 200mbps will start dropping packets causing the overall throughput to drop. Might not be exactly you situation but wroth trying.
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