(Re-)entering UK academic system after a long time abroad
It is not true that there are no research only academic posts. There are post-doctoral researchers, research assistants and research only professors in many places within the UK academic system. There are also research institutes outside universities and affiliated with universities who wholly perform research.

It's just that there are fewer advertisements for  these posts as there are fewer of these types of vacancies than teaching lecturer posts. You could get the impression  that they do not exist based on reading job advertisements alone.

You would need to research more carefully what institutions are performing the research in the specific area of your skills and try to find out how they advertise.

You should  be aware of the UK Universities own vacancy notification site www.jobs.ac.uk as traditional advertising of vacancies (such as in scientific journals and newspapers) is no longer performed due to budgetary reasons.