One of my Seargeant Juniper ( my shohin comp tree) has develpoed brown tips to much of the foliage. Some are nice new bright green, but others are brown

Has anyone seen this and maybe know what the cause?
Not Mites ( tapped aver paper and no signs of them, no Bugs or other horribles that i can see.
foliage has not been cut
Only happening to one tree, the one on the bench next to it is fine

Ken