@Hudders Hi, Did the modem work with your three SIM cards before? If it never worked, please help me check the following information: 1. make sure the SIM card is firmly...

@CzKenz Hi, I see that your current network type is WCDMA which belongs to 3G service. Have you checked with ISP-TRUE-H whether your current SIM supported 4G bands? Or if the network mode is 4G...

@zwiebelchen89 Hi, comparing with MR6400, I think M7650 or M7450 would be better since it has battery for power supply. https://www.tp-link.com/en/home-networking/mifi/

@xHal9000x Hi, since this is an ISP customized model, the management page is not the same as the general model and some features might be blocked by the local ISP. It is suggested that you could have...

@Shaya Hi, I see the model number you choose is Archer AX1500 which did not support VOIP. So did you select the wrong model? And May I know why you want to change the locale selection?

@Orvi Hi, It is suggested that you could change the DNS to be 8.8.8.8/8.8.4.4 under Network>DSL WAN interface>Edit