I just came across this post and I'm having the same issue all of the sudden. my Corey are huge diggers - lately more than ever (laying eggs a lot more too). My sword is pretty large and about 4 years old. Do I need to trim the roots or just keep pushing them back in? I have 3" of sand but just got another bag to add.How deep is your substrate? Swords can get pretty big. Perhaps the roots have just doubled back, having no where else to go?
It probably has plenty of roots below the surface. I have a large sword that does that somewhat and the substrate in that part of the back of the tank is ~5".
I agree, in my experience, 2" of the substrate is not enough for swords when they grow big. Also, you're issue isnt coming from a single reason. The substrate depth in addition to the fish digging around all work together. Just add another inch of substrate and you should be good.Substrate is not deep enough.