Check in your network mode settings and change LTE/WCDMA/GSM change it to GSM/WCDMA or WCDMA only. If not this is often times a bad sim or sim reader. Make sure that the contact between the sim and sim reader is good.
Could be the charging port needs to be replaced. I've seen this issue before. We manually unbent the charging port pins and voila! Also did you try the obvious of trying a diffent charging cable/wall charger?