Can't send/receive texts to/from non-iPhones

[Supermallet]

Just recently my iPhone started telling me that texts sent to phones that aren't iPhones have failed to deliver. I'm also not receiving texts from people who don't use iPhones. This is a problem sending texts to people on my own carrier (Verizon) and T-Mobile as well. I haven't tried to text anyone without an iPhone who's on AT&T, but I'm guessing the problem would be the same.

I did some searching and found two possible culprits: Using LTE calling on Verizon and having email addresses listed as send/receive options in iMessage. I disabled the latter, so only my phone number is checked as a message option. I checked my LTE settings and they're sent to data only. I have send as SMS enabled. Yet I still can't send or receive texts to people without iPhones.

Is this an iOS 8 issue? Has anyone else had this problem? Any solutions?

 

[Supermallet]

I found that if I disable iMessage, I can send someone a text, and then after re-enabling iMessage, can converse with them as normal. However, I'd love it if I could fully fix the problem instead of using a workaround, because that's a pain to do and I don't think it will help for someone who's texting me without me having already texted them.