Is the Belgian bank losing money compared to the UK one? Is there state intervention?
They just don't tend to sell very well - when interest rates are low [1], it's not particularly appealing to fix at 2.69% for 10 years when you could fix at 1.94% for 5 years or 1.25% for 2 years.
And coming off the back of two decades of rock bottom interest rates, a lot of people didn't anticipate that they'd be remortgaging at a >5% interest rate.
[1] https://web.archive.org/web/20170921064712/https://www.barcl...
It’s basically hedged with long term bonds (Belgian or European) + a profit margin for the bank + risk based on your profile (age, health, employment history, …)
I guess UK banks are just hedging with shorter term bonds compared to Belgian ones.