I have a similar problem. At first 17.3 beta worked fine, then later maybe it was updated then broke wifi completely including the cellular data. When 17.3 production was available the phone was completely wiped & restored from backup and 17.3 Production was installed. At first the wifi worked, then within a few minutes it breaks completely. This process has been completed twice with the same results. Anyone know a solution to this? Would installing 17.4 beta fix the wifi issue?