Are your renders glitching out with triangles which you cannot see in the viewport? Just automatic map them and it should work.
Watch video How to fix weird hard-edged triangles in my renders on smooth models online without registration, duration hours minute second in high quality. This video was added by user CGI Tutorials (Ben Shelley) 04 June 2020, don't forget to share it with your friends and acquaintances, it has been viewed on our site 471 once and liked it 11 people.