Regarding connection speed, unfortunately, we cannot guarantee the high-speed at all the time because the original network is under control by NTT Docomo.
Internet connection speed may vary depending on the following reasons:
- The steel structure of mansion/apartment (it may hinder internet speed.)
- Device internal memories are fulled or Old model smartphone which can not support 4G/LTE.
- Weak signals due to adverse weather conditions
- Docomo coverage in your area is not stable.
- Network congestion during peak
Please make sure to prioritize for 4G/LTE speed on your mobile cellular setting. You can try to reinsert your SIM card again and check whether it works or not.