Haha ok, so I was doing something really stupid. Basically I thought that the hash was the actual password. Thanks for clarifying that 
I've reset the password, reverted back to tlschallenge and basicauth is indeed working:
2024-02-28T15:05:25+01:00 DBG github.com/traefik/traefik/v3/pkg/middlewares/auth/basic_auth.go:86 > Authentication succeeded middlewareName=myauth@docker middlewareType=BasicAuth
Only one ERR remaining in my log now, how do I fix this one?
2024-02-28T15:04:06+01:00 ERR github.com/traefik/traefik/v3/pkg/provider/acme/provider.go:399 > Unable to obtain ACME certificate for domains error="unable to generate a certificate for the domains [traefik.continental34.com]: error: one or more domains had a problem:\n[traefik.continental34.com] acme: error: 400 :: urn:ietf:params:acme:error:connection :: 24.132.61.220: Connection refused\n" ACME CA=https://acme-v02.api.letsencrypt.org/directory acmeCA=https://acme-v02.api.letsencrypt.org/directory domains=["traefik.continental34.com"] providerName=myresolver.acme routerName=mydashboard@docker rule=Host(`traefik.continental34.com`)