I think i messed up

I allowed my parents to store their btc in my ledger. So technically this is now showing as them selling their btc to me when they moved it to the ledger... and subsequently shows as if im selling it when i move it back to their exchange for them to sell.

Any thoughts on this? We have full documented buy and sell dates and exact figures of how much each person has but i worry im going to have to now pay thousands in tax because i let them use my ledger

Im in the UK.