Gutter, not fifth wheel related but it is about eternabond

So been chasing a leak in my house gutters, found out it is an inside corner of the gutter that was never sealed properly, this is all work done before we bought the old place, so my question is would eternabond be a good way to seal where the corner is?
If I run it up the seam and across the bottom and up the other side I figure it has to be better than the way it was done with caulking that was filling what turned out to be a very large gap, really not a good job done by installer, and of course the caulking after all these years deteriorated, and slowly showed a problem, so would this be a good fix?

Thanks