HeeWing T1 VTOL 'tumble turn' when RTL requested

Hi - I have a HeeWing T1 VTOL with F405V2 FC running Arduplane 4.5.7.
I’ve noticed that sometimes when I switch from FBW roll stabilisation to RTL the T1 will perform what looks like a very unnatural (from fixed wing RC point of view) manoeuvre that looks a bit like a pool swimmer’s tumble turn…is this normal or do I need to autotune some more? I notice an ‘overshoot’ remark in messages…maybe this is implicated? This link is to a tlog as F405v2 FC only has small data flash memory on board so no bin file…