Been having issues sending MMS every since I got my Nexus 5 (late December). Get a "Failed: Long hold to check APN settings". It's sporatic at best. No real pattern to pinpoint when/where it will or will not send MMS. I've done a bit of reasearch, but no real answers. Any ideas on a fix? Looked to be a common issue after initial launch, but I can't find much on it recently. Unrooted phone on Sprint using ChompSMS.