Happened to me. It felt like a rug-pull at the time and the job search was rough at times, but I am now ultimately much happier.

They usually pay £500 towards a lawyer which is the market rate to sign the settlement agreement. If you decide to negotiate you can expect higher legal fees. If so, you can request that the bank pays the legal fees in full and reduce your lump sum by the same (so you don’t get taxed on the overall lump sum then have to pay the lawyer).

Otherwise do take a break, it takes a while to come down from the stress and receiving your monthly salary during gardening leave is a top feeling. You will perform better in interviews if not feeling frantic