Hi @Sk1904 - if your SIM swap has successfully ported your old number to the new SIM and phone, any messages sent recently while offline should come through in a few hours. This is because when text messages are sent but cannot be delivered (ie phone is off or SIM is out of the phone), they are stored on the carrier's network systems for a (short) period of time. After that time period, if they still cannot be delivered, they will be discarded from the network.
There is also a chance messages sent were lost during the number swap-over to the new SIM - these will be lost, like tears in the rain, sadly.
The message servers will keep trying to deliver sms for 30 days.
MMS messages will be retried for 7 days from when they were sent originally.