Monkey Puzzle white sap and brown branches issue

Hello all,
We are looking for some experienced advice. Over the last 6 months our monkey puzzle has had white sap seeping out of it and 3 branches now turning brown.
I can't see any obvious reasons myself but would appreciate anyone who could look over photos and perhaps help with advice.

It has been in a large pot growing well for a few years now.

Thank you very much

 

Most likely needs a larger – much larger – pot. Or even better, plant it out directly into the soil.

 

Maybe it froze during the winter.

 

Thank you for your fast help.
We didn't have the space to plant it ourselves but will plant it directly into soil and see how it goes.

 

No - it's been one of the mildest winters on record in Britain. Think the lowest I've had here is -3°C, perhaps -4.

 

I overlooked the little, tiny "uk" on the opening post.