I was using the beta firmware, the new version was not reported to me. Thanks for giving this information. I downloaded and installed this v1.3.0_0.9.1_[210608-rc66100]. Alas, no more manual...

@222jacky My router is arranged vertically, maybe this gives it good ventilation and better 4G LTE reception with the internal antennas? The standard power supply has been replaced by a mini UPS to...

@222jacky As I understand, you are saying that the router restarts or stops working when it is overloaded by a speed test? - Maybe its processor is overheating? Make sure the router is properly...

@Shaan15 If the MR200 is not covered by TP-Link warranty anymore, you can try to open it. Perhaps, you'll find a bad capacitor with bulge inside. If so, then you should try to replace it. To give an...

@sgaiger It's looks like a harware problem. Try to use another 12V/2A power supply to start your router. If it don't works with the new power supply, perhaps it's caused by a bad capacitor inside...

Did you tried to: - do a FACTORY RESET by pressing the reset button 10 seconds? - remove the SIM card and reboot without it?