Nothing has changed from your point of view.
You had a tracker mortgage at ECB +x%.
You still have a tracker mortgage at ECB + x%.
Start can't take you off the tracker, but if you want to fix, they might not offer you an option to fix. ptsb does offer such options, but their rates are not really attractive.
The price Start paid is not relevant to you.
Yes, the security went to Start.
If you are in a position to switch to another lender, it's possible, but extremely unlikely, that Start might give you a discount to do so. Ask them, but don't be offended if they laugh at you.
You might choose to switch to another lender anyway if the margin is high. But are you in a position to switch to a repayment mortgage?
Brendan
Brendan