Restoring new phone WIFI Issues

I just got a new iPhone15; during the setup, I was able to connect to wifi and begin the iCloud restore. Sometime during the restore, the wifi connection dropped. The wifi is working with my other devices and worked with this phone before as it was my wifes. Every time I connect to our wifi, it connects for 5 seconds and then drops. I have tried numerous other wifis and it is not working. I have restored settings and reset the modem, but I can't install the upgrade until the restore is completed. please help very frustrating