Looks suspiciously to me like Russian vine aka Mile-a-Minute plant. It flowers briefly, seeds prolifically, grows like the clappers (gets huge) and is and unattractive menace for 50 weeks of the year. I would pull it out and keep an eye out for any seedlings.
Vendée - 20kms from Atlantic coast. "We don't stop playing because we grow old; we grow old because we stop playing." - George Bernard Shaw
Posts
"We don't stop playing because we grow old; we grow old because we stop playing." - George Bernard Shaw
https://www.google.com/search?q="fallopia+baldschuanica+"&client=firefox-b-d&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiB_I7MiOjyAhX8QEEAHfMFBfEQ_AUoAXoECAEQAw&biw=1280&bih=595