ASK: The R58 4G Industrial Router's Port​​​​​​ forwarding not working

ANSWER:

1)  Check with ISP which ports are open by them

2)  More than 1 router. The most common problem we come across is people who are behind 2 or more routers and don’t realize it. So here is a quick step by step.
Step 1. Login into your Router.
Step 2. Find the status page that shows the WAN/Internet IP address and write it down.
Step 3. Log into the first router/modem now.
Step 4. Find the DMZ page.
Step 5. Enter the IP you wrote down into the DMZ page and enable DMZ.
Step 6. Save and your done.