Q.Trachelospermum Jasminoides- Leave Disease
Good afternoon, please, you can tell me what disease it is and its remedy? I live in Anzio-Italy. Thank you very much and hello Giuseppe

Certified GKH Gardening Expert
It is very hard to say from that picture alone. It looks to have been a pH issue, or possibly overwatering.
Here are some article that will help you to know what these plants require:
https://www.gardeningknowhow.com/ornamental/flowers/jasmine/star-jasmine-as-ground-cover.htm
https://www.gardeningknowhow.com/ornamental/flowers/jasmine/pruning-star-jasmine-plants.htm