Retrospective record - Cubase 11 - garbled inconsistent results

I use this feature a lot.
But I’ve noticed that if I say play for a few minutes and then capture something as retrospective record… then the result is inconsistent.
But often what happens is it sounds like two passes superimposed on each other, at least for some of the resultant region.
Does anyone know of any specific settings that control this sort of behaviour?

[NB: My typical use is I’m busking along or rehearsing little licks in the writing process - then something unexpectedly feels worth laying down and retrospective record is a true saviour for this - so sometimes the transport will be going, and sometimes it won’t be. ]