There are literally hundreds of Hosta varieties, and without a scale to indicate the size of the leaves and height of the plant, it's hard to make an identification with any confidence. I think your best bet might be to contact experts in the British Hosta and Hemerocallis Society who can advise further. But you'd need to include the information mentioned as well.
@Braidman Reminds me of Hosta June. Yes there are so many.June was so popular when it was introduced twenty years ago, you could find it in every Garden Centre.
I have worked as a Gardener for 24 years. My latest garden is a new build garden on heavy clay.
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https://hostahem.org.uk/
When you don't even know who's in the team
S.Yorkshire/Derbyshire border