Had the same problem with a Zanussi last week, cant remember exact model. After doing all the same tests you have done I bit the bullet and ordered the PCB and just in case also the NTC.
Result phew!!
pcb doesnt have to be burnt to stop working. did zanussi couple of weeks ago. get a very good look at relay contacts these seamed ok but were infact cracked around joint. resoldered and away she went with original relay.
If it’s an older machine it’s worth replacing the relay as the contacts will probably be burnt. On newer machines (2/3 years) the solder joints are probably all that needs doing. Same with washing machine heater relays.
Mike.