British Columbia: Help with container Wisteria - swollen roots (root galls? club root?)

Hello dear forum experts,

Our container-grown Wisteria is not growing new shoots and when uprooted to diagnose, we found what I believe are called root galls - swollen and distorted root sections which are hollow and papery. Posting to see if anyone can help identify what's wrong with our wisteria and how we can help it?

The background: Wisteria was brought inside last winter 2019 (we are in Vancouver, BC, but since it is grown in a pot, figured it was safer for roots to be inside) after having lost all leaves. Late winter, while inside, the wisteria began to grow shoots and new leaves, and by February it was nice and lush like below:



Around March/April, we moved the Wisteria outside onto our balcony as it was getting quite warm, but it began to lose its leaves and never came back. When uprooted to inspect today, we found these swollen roots as below. The soil is slightly moist, but roots do not show signs of rot -- they're not mushy, wet, or odorous. The swollen root sections are hollow, papery, and dry. Should also mention that when the surface of the trunk is lightly scraped off, the trunk appears green underneath.

I've been reading up on crown gall and root knot nematode (tag based on what is being viewed. We filter the output of wp_title() a bit - see agriflex_filter_wp_title() in functions.php. --> <title> Wisteria | Texas Plant Disease Handbook) but not sure if either of those are it?

 

Nitrogen fixing root nodules like other pea family plants have.

 

Thanks Ron, so these are actually normal/healthy nodules then? That would be a relief!

But in that case the question that remains is, why does our tree remain leafless and barren this far into the summer? And can we/should we do something to help it recover and grow?