@davel Your break fee should be zero, but confirm it with Ulster Bank (and please post it here when you receive it).
Switching immediately to Avant's 1.95% rate fixed for up to 7 years will save you about €2,800 over the next four years (versus staying on UB's 2.2% rate), and that's after accounting for fees and cashback.
Of course, if you decide to stay with UB, you will probably want to switch again in 4 years when your fixed rate expires and your mortgage moves onto Permanent TSB's books, at which point you will be subject to their (probably higher) interest rates.
The above savings estimate assumes that you start the switch to Avant before the end of March and use a broker who is an Avant "Gold Partner", so that you are eligible for the €1,500 cashback.
If you're feeling brave, you could consider the strategy outlined in
this thread: switch to Haven's 2.35% 3-year fixed rate and get the €5k cashback. Then quickly switch to Haven's 2.0% green rate. If it works, you will be better off by about €5,800 in four years' time (versus staying on a 2.2% rate with UB). Nobody knows for sure if Haven will allow you to do this, so you might be stuck on the 2.35% rate, which isn't bad considering the €5k cashback.
If you're prepared to settle for smaller savings in exchange for a longer fixed rate, consider Avant's 2.1% rate, fixed for 10 years.