Manchester serial decoding does not work for the output signal from my TSOP33436 IR receiver (RC5 protocol). Instead of positioning the first bit at the first transition (which is from +5V to 0) it does so at the second transition. The results are wrong packet length (13 bit instread of 14) and wrong data.
I think the start flank is missing in this signal.
Every example I have found has a halfway signal when idle and has a edge half the amplitude as a start of package timing trigger. Also if you count the full bits then you see the first bit should have a staring edge before the first edge.
Something I have added in red in the below scope image.
I have also exported to sigrok and gave the same inconsistend timing result.