ZyXel router randomly loses connection

I bought this ZyXel LTE 3301 router for use with a SIM-card which is also new. About 1-2 weeks ago the router started acting up, cutting out or getting insane lag (pinging google.com via cmd.exe gave me 3000+ ms). A restart is always required to get it working again.

Things that couldn't be the problem.

  • SIM-card (New as previosly stated)

  • ISP internet speed or MB restrictions (I have unlimited data from an old subscription and my parents with a subscription from the same ISP never experience these kinds of drops)

  • Router connection to ISP (Built a mountan of cardboard boxes to have a constant green connection)

  • My Windows 7 PC (All devices - Phones, macbooks, AppleTV - cut out at the same time)

  • Ethernet cable (See previous note)

  • Router software (Installed the latest)

What it might be.

  • A setting in the router control panel (I try but I relly can't understand 90% of the info in there)

  • A randomly broken router (Might be caputt from heat or from factory. Never dropped the router or anything)

  • The router might just be an expensive veggie for all I know.

I would really appreciate any help to learn to troubleshoot the router or to simply remove the need to ever troubleshoot by fixing it. My current TS is just pinging google to confirm that it's not working and restarting.

Thanks in advance.