no, not at all. I sent them another troubleshoot file and have one extra prepared but there is no answer from Teltonika R&D.
We have found that it is combined problem of Telotnika and Operatora (as I mentioned - Operator told us that it is modem installed into routers fault).
When we took SIM of Teltonika (broken) router and put it into other device the SIM card registered to network. Few times that SIMcard worked into broken router after putting it back but only till first reboot. It look like SIM card could not be registered to network in these Teltonika routers (we have few of them) only in these specific location (BTS: LTE's bands dependent).
We've asked Operator if they are blocking devices or SIMcards - the answer was: no.
In my personale opinion the problem is with LTE bands that Teltonika routers does not recognize well and cannot register to networks.
We made a test and took one broken router out of BTS range when the router works fine in other LTE channel. But when we took it back to the station the router again could not connect to network (with and without APN). We check other Teltonika router with that SIMcard and it worked fine at the first try... same with mobile phone test.
Because of some reason these Teltonika routers do not deal with automatic change of network channels.
Event when we fixed the channels at WebGUI, it does not help.