Metalcore-pop band similar to issues

If you want weird metal try Baby Metal.

I don't know something exactly similar. I like Amaranthe and it combines a pop-y sound with power metal. The first album is especially considered more pop by some: Amaranthine and 1.000.000 Lightyears from that album. But it's not exactly like Issues and there's still some growling.

Edit: Later albums actually have less growling. For example True, Exhale have no growling.

It sounds pretty similar to Dream Theater for me. I'd recommend you take a look at a fair bit of their stuff before you judge, they can be pretty diverse. They're generally categorized as Progressive Metal. My personal favourite album of theirs is Six Degrees of Inner Turbulence. Sadly, it's rare to find people who can actually understand that album properly.

Edit: After listening some more, my recommendations is way off. Maybe check out Hands Like Houses? A friend pointed them out to me when I asked, seems pretty much like what you're asking for. https://www.youtube.com/watch?v=5NSIf7F7uMQ

Maybe tis could help? http://www.last.fm/music/Issues/+similar

Trapt
Coldrain

On top of my head it looks like "We came as romans" or "of mice and men".
Also check "The Dillinger Escape Plan" for the mathcore aspect: http://www.dillingerescapeplan.org/content/option-paralysis