Check your Passport and Visas first before travel

The Isle of Man is not part of the UK or EU.

This means IOM citizens have no equal right of work in UK/EU so would likely need work visa into UK/EU.

This means UK/EU citizens have no equal right of work in the IOM and would likely need work visa into IOM.

Work permits

The reason for saying this is that you need to double check your visa status and not assume it's okay as an EU citizen!

Check:

If your passport and necessary visa is not right it is not the fault of the travel companies. You are responsible.

The airlines could refuse you travel which will likely mean you miss the event and lose money of holiday lost.