New info:
Test 1: removed duplexer, ran paper path test on legal and it worked.
Test 2: replaced duplexer, ran paper path test on legal and it failed.
Test 3: removed duplexer, ran paper path test on legal and it still failed.
I power cycled the printer between each test.
Test 1: removed duplexer, ran paper path test on legal and it worked.
Test 2: replaced duplexer, ran paper path test on legal and it failed.
Test 3: removed duplexer, ran paper path test on legal and it still failed.
I power cycled the printer between each test.