Why do my lines and other chart objects disappear when I change timeframes?

Be sure that when you are placing chart objects on a chart that you are not drawing them past the last and updating candle. If you do this Alveo does not have solid data to use in order to create the object, so it will bug out and disappear.

There is also a possibility that the object still exists on your chart, but you are viewing a section of the chart where the object cannot be seen or on a timeframe that is inappropriate for the object.