Recently repotted JBP has browning needles

[Bonsai Nut]

I think the only thing you can do at this point is to wait and see what happens.

This is the best advice. Pines have an annual rhythm where you do work in certain windows of time based on season and where you live. You have to be very careful not to overwork them. If you repot, particularly if you trim roots, you should not do any work to the top of the tree until it has recovered from being repotted, and that normally means to wait a season before you pull needles or prune or cut candles.

Fortunately Japanese black pines are very strong trees. It may recover. But don't do anything else to it this year.

 

[Wulfskaar]

I like to check the What did you do today? thread often. You can see what people are doing at any point in the year. It's interesting to follow and it can be a helpful guide.

 

[The Barber]

Did you bare root it? That could also cause issues.