This looks like a bug to me. Does it do it on the daily? Next time I'd monitor that as well. It's possible that the bug resides in their use of OHLC on a not completed DAILY bar which is then rolled up into a weekly bar (but the OHLC calc had already been done prior to the rollup).
After the session is closed or chart reloaded is everything correct?
After the session is closed or chart reloaded is everything correct?