21-05-202310:50 PM - last edited 21-05-202310:56 PM
Is your Fold a US version? The non US versions are dual SIM whereas the US version only has single SIM.
If you have a dual SIM version and your SIM is showing as SIM 2, then you need to put the SIM card in the opposite side of the SIM tray. If you look at the SIM tray, you'll see it labelled which side is SIM 1 and SIM 2. Typically face up is 1 and behind is 2.