Also, what is printed on your 153IR manual for the 2021 version? In fact, how do you know it's a 2021 version? As of today, the Lionel site only shows 2 manuals for the 153IR:
There has been much frustration, consternation, etc. with the 153IR wiring as the hookup instructions have changed between versions even though the Item # stays the same. Even the manual reference number has a mis-match on their documents list for the 153IR!