For business purposes, I have an Asterisk PBX set up in my home office. It uses SIP trunks and I can administer it remotely over the web (with a dynamic DNS config). My issue is this: I use an xLite softphone app on my laptop; it work fine almost everywhere I have Internet access except when I connect via my Verizon hotspot. This is a serious issue for me as it is impacting my business. I know it's not the softphone config since it connects as soon as I connect on another network (typically, in a client's office). The main reason for even getting the hotspot was to deal with locations where I might not have Internet access. My own thoughts on this is that Verizon blocks SIP apps, but I haven't found that explicitly yet.
So, I found myself in the ridiculous position of spending money to lose business.
VZW does not discriminate against specific apps. Instead the NAT firewall on the new LTE network is most likely to blame. The NAT makes all devices appear to have the same IP address which makes routing for softphones, webcams and gaming consoles very difficult. Basically anything that depends on a unique IP address will not work on the VZW LTE network.