Unable to make and receive calls and 4g not working at home on all 3 SIM plans at home.

Hello all.

I have been a smarty customer for quite some time and recently 4G has stopped working and unable to make or receive calls indoors at home. It's nothing to do with the settings on my phone I believe as I have double check this as I have a s25 ultra my wife has an A55 Samsung and my daughter has iPhone 14 and it is the same case with all three phones.

My phone will only allow me to make and receive calls and go online if there is 5G indoors and outdoors.

It has been over 2 weeks and have complained to smarty where they keep saying they are looking into it and nothing has been done. 

Can someone please help me on this?