Well I think it might be more then just a water issue.
Mine turn yellow and brown , working it's way up the trellis.
Watering was fine as I paid attention to that . During this drying up peiord I noticed something.
HEAT ... It was very HOT , not only hot it was very humid 88 temps ,real feel 90's.
I think the extreme heat had a role in it and the plant could not keep itself cool enough and burned up. Even with good watering it just could'nt keep up .
They do say not to water in the heat of the day cause of scorching . Mine is up against the house so the extra reflectivity might be something too.
...just some tought
snow