Hello Juha,
I have a TS-480SAT setup and, in parallel, a twin TS-590S setup.
I use a Netgear Nighthawk mobile Router with 4G/LTE.
Both RRC-1258 MkII setups work fine with the Firmware 2.95. / Bootloader 1.10. I work CW for most of the time.
I can configure the COM3(Extra) serial port to either serve as a Winkey for CW or for RTTY to key my TRX with FSK.
This is very handy with N1MM+, F1 sends CQ, F2 the report etc.
For all of you having problems with the setup, please have a look at my screenshots here:
https://qsl.net/hb9bjl/Some screenshots might be useful for your K3 setup as well. I hope this might help you.
You can send me a e-mail to
hb9bjl@bluewin.ch .
73 de Christian, HB9BJL