HI folks. Would appreciate any advice. I use the Three network in Ireland for SIM broadband due to my rural location. I recently upgraded to 4G/LTE SIM plan but their Hwawei router gave a poor signal (<1 mbs download at times). I borrowed a friend's TP LInk MR6400  the signal was better (3-7 mbs download - still brutal, I know!). So, I went and bought a new router - Archer MR600. Same location in room, signal only gives 0.6-1.1 mbs download. When I slip out the SIM  card and plug back in to the MR6400, it's back up at 5-7mbs download speed. I've repeated this a few times with consistent results. I followed all the installation instructions, rebooted and reset the MR600 several times, but still no joy. Feel like I'm missing some small step somewhere - any ideas/solutions? FIrmware is up to date etc.  Many thanks.