What is this plant that's growing alongside my blackberries?
EDIT: So many comments! For everyone who is sad that I may no longer have blackberries, don't worry! There are still like four stalks just like the one I pulled up, in addition to the giant bramble of vines that already produce fruit every year. This is just the first time I've ever seen any new growth, so it was confusing to think it could be the same plant. Thank you for the feedback so I know to leave the rest of the stalks. Appreciate y'all and can't wait for these to mature!!
I went to put our blackberry vines on a trellis and saw this growing up between some of the vines. I assumed this plant was a weed of some sort and yoinked it, but the plant ID app I used says it's also a blackberry plant? I obviously don't put a lot of stock in the results of these apps now that AI has kinda poisoned them, so I figured I'd ask here.
Glove for scale in first pic and the third pic shows another one alongside the main blackberry vines. Should I pull the other one? Leave it? The "normal" vines popped up on their own from a neighbor's yard so we didn't plant them, and I hardly know anything about them.