I’m nervous because some browning has started to appear. I’d had my bonsai over a year, and didn’t had this problem before.
Can you advise please?
Thank you!

where are you keeping it?
How do you care for it?

I keep it outside, in a balcony.
I water it every other day. More than that, I don’t do much.

I had a juniper for close to thirty years that grew vigorously in one area and turned brown and died in another, completely unpredictably. I never pruned or trained in any way because I never knew if what I cut off would be the only living branch. It looked pretty nice, with live branches twisted around dead. I don't know the species, just a ground cover sold at the local nursery.

Then my neighbors turned off the water going into my timed watering system.