Swollen stems.. What is this?

Ok so not sure what this is, has anyone seen this before? I thought re-vegging at first due to the odd growth at the tops but the lower parts seem to be growing as normal.
Any help here will be appreciated. Cheers in advance.

1st photo is the swelling
2nd is top
3rd is the lower parts

im just guessing here, but i think theres ruderalis in your strains genetics, thats the only thing i can think of, ive never come across that one before.

Sometimes after topping or a Fim , actually most of the time the lower nodes plump up as response to the chop. Since your in flower maybe you didn't notice til now? Just tossing ideas

Kinda like that

its possible that its affected the whole stem instead of just the nodes.