That is leaf burn, (sunburn) it is brought on by lack of
water and to much sun.
How long have those bushes been planted in that area? do they get a mix of sun and shade or just full sun?
do you have at least 4 inches of much around them? That helps with moisture retention and helps keep competing weeds away.
Blue berries have a 1 foot deep root system, like to wild establish in partial shade areas or edges of forests.
If they are in full sun the leaves will tend to get crisp around the leave edges (as in your photo) unless they have a deep enough litter (mulch) around them.
Lack of acidity will also cause a browning of the leaf rim, manganese deficit will show itself as reddish leaves. (Epsom salts will correct this)
Most bushes I see with issues also have a lack of acidity in the soil.
I use a 1 inch layer of spent
coffee grounds on the soil and cover that with a 1 to 2 inch layer of leaves and top off with 2 inches of
wood chip mulch. this adds acidity long term, holds moisture and provides nutrients from both the grounds and decaying leaves.
I usually water once a month with 2 gal Epsom Salt water per bush slowly poured through the mulch layers so they aren't disturbed. I water once a week or twice a week depending on weather and if it rains enough I don't have to water.
Where I live the air is very hot and humid, something the berries like if they have enough shade during the day.