Thank you @darthviper107 ! However I still have this issue: as I understand, Lightmap resolution is lower on those blue edges. In some models it happens even widther, so sometimes it generates some shadows in wrong places or illuminated zones:
I have tried with this free and easy-to-download model, so you all can test too, if you want: https://free3d.com/3d-model/sofa-malagasy-58678.html
Best regards!