It seems a bit nit-picking that you are allowed a slightly bigger bag if you pay for priority boarding BUT as long as it's in their terms & conditions which you should read before booking there really is no complaint.
When I book plane tickets I always check the baggage size and make sure my bags will fit. Every airline has its own policy on bag size and weight so you really do need to check
I'm not sure why you call this a rip off. Would be interested to know what you'd be paying if you went this route with another airline. With all their 'rip-offs' and costs that annoy they are (or were pre-covid) persistently cheaper than any other airline.
They are the only direct flight from Faro to Porto and though early or late the best time. The fact that last week the bag was allowed and this week wasn't is the issue