I have tried many LTE sticks both pppoe and hilink but they are all kind of unreliable. I don't mean the LTE connection which is super reliable - the sticks hang and reboot! I know that one option is a Routerboard with minipci LTE. What else is there to buy in EU? Reliable sticks? some wired LTE router?

Please share your experience!

Thanks!

I use a Huawei B593 connected to a RB750 used as a openvpn endpoint. It has been running since June, when it was installed, without need to reboot.