Q.Table Grapevine
I have a grafted climbing grapevine about 6 years old that produced wonderful fruit in Oct. It grows over a trellis. Since last year the leaves turn pale green and has not been growing rigorously as it had done in previous years. Can anyone identify the problem and how I can remedy it or is it too late for this season? Many thanks in advance.

The articles below will help you pinpoint the issue.
https://www.gardeningknowhow.com/edible/fruits/grapes/treating-grapevine-problems.htm
https://www.gardeningknowhow.com/extension-search/