This was an old issue (Nov 15, 2017) for which "Comments are closed". You need to reopen it.

Originally it seemed that this problem was due to using old OS such as Internet Explorer. Now it's occurring again, this time with Edge.

Using Edge, I had 5-6 stocks that I was comparing on a Dow Index chart. When done, I closed the chart. Later, when I opened the Dow Index chart to compare other stocks, the first two stocks from the first comparison were still there. I've tried clicking on the stocks delete "X", logging out, etc. These two "ghosts" just refuse to go away. I tried opening a S&P Index chart, the same two ghosts showed up there also.

I tried entering a duplicate of one of the ghost tickers to the chart. It took that, and I could then delete it by clicking on its delete button. But the original ghost ticker stayed on the chart. I then tried re-entering the duplicate sticker, this time clicking on the ghost's delete button. This caused the new duplicate sticker to go away, with the ghost remaining in place.

If it helps any, like the original problem, it seems to create two tickers - I've not seen it to cause 1 or 3, 4, etc. ghosts.