Song.Transport.Playback_Pos Problems

I’m trying to debug a problem in the custom pattern jump navigator, but it seems i cannot debug it from within the script.

(script attached with all debug and proper mode already initialized)

The routine is:
Recalculating the new position on the next pattern if a current recalculated jump position would exceed the current pattern-size of the current selected sequencer position.

This works fine, as long as the next pattern size is equal or larger than the current sequenced pattern.
However, if the next queued pattern is smaller, the position will always be set to the last line and my positions are ignored.

The tool is set to jump a factor of 25%
I usually assign these shortcuts to shift+alt+pgdown and shift+als+pageup
Starting with the pattern editor cursor at line 00 i jump down in steps:

Sequence 00 patternsize 64 00, 16, 32, 48
Sequence 01 patternsize 64 -> Transition works, jumps to line 0 (00,16,32,48)
Sequence 02 patternsize 96 -> Transition works jumps to line 0 (00,24,48,72)
Sequence 03 patternsize 32 -> Transition does not work:Jumps to line 31 (The scripts says it shall jump to line 0)

And there is no kind of magic that i can apply to force it to jump to line 00 on the next pattern.
You can see for a moment it does jump to position 00 but directly after, it jumps to the last position.
This really seems an internal Renoise problem somewhere…

When going up, this problem is not occuring.