Looks like the latest commits for free5gc-compose (related to v3.0.3 release) broke something for the n3iwf component:
n3iwf | ERRO[2020-07-24T18:17:59Z]/go/src/free5gc/src/n3iwf/util/initContext.go:45 free5gc/src/n3iwf/util.InitN3IWFContext() No AMF specified N3IWF=context
n3iwf | ERRO[2020-07-24T18:17:59Z]/go/src/free5gc/src/n3iwf/service/init.go:102 free5gc/src/n3iwf/service.(*N3IWF).Start() Initicating context failed N3IWF=init
n3iwf exited with code 0