Crazy bars - uk supermarkets

ok, i was bored, looked at a few uk share charts. anyone plz tell me wth are these bars and are they tradeable and how bad is the spread or how do i find out please? does this happen for a reason? is it just bad or incomplete data or something else? thanks. thanks.

found another broker with tesco charts, they do not have these bars. so either it is bad historical data from broker, or broker had some kind of pricing liquidity issue or something. curious if such a price would be honoured… could be like nfp every day, lol.