Hi Chud, I had this problem a while back and it drove me mad, see the thread below and see if the suggestions work for you, they didnt for me but have another poser version now that doesnt do it, http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3781059&ebot_calc_page#message_3781059

 

 

Tools:- Win10, Dell XPS8900, ZBrush, Marvelous Designer 11, Hex 2, PSP8. PSP 2019 Ultimate, DAZ Studio, Affinity Photo, Affinity Designer, Filterforge 11, flowscape,  Classic UVMapper, and several headache tablets.