I should have stated that there are several of these spots on a couple of the plum trees.
They could be old cicada wounds. Was 2-3 years ago a big cicada brood hatch there?
If that is the case should i cut off any limbs that look like this?
if it was my tree i would let it be. It seems to be healing well, and if there may have been an infection it was a year ago already. Besides, pruning would be an additional entry point
Yup, looks like cicada damage. I just had the 17 year cicadas in my region last year. On smaller branches, those wounds would cause dessication and become brittle and break off after a couple months. On larger branches, they heal over. I would only prune off any that are on thin, outer branches or any that feel like it’s causing a weak point.