First, use the F5 button to refresh the chart then check again.

This gab may happen because you rollover the new oil contract for different symbol, Example: you used Nasdaq symbol setting and change its source to new oil contract, then the chart will start drawing Oil prices after Nazdaq prices which cause the gap or the difference.

If you want to add new contract we advise you after adding it to pair it with the previous contract “use the option paired with previous oil contract from you Edit the symbol from the Symbols Settings” to let the chart continue drawing price line in the same price range.