What is the problem?

If I use the Insert link dialog to enter several links in a row, I find that the search dropdown no longer appears correctly. For example, in the screenshot below, it appears "behind" the dialog.

It normally happens when I try to enter the 3rd to 5th link.

I have only seen it happen when entering the full URL to a page on the same wiki as I am editing.

Steps to reproduce problem

Repro one:

1. Open the 2010 wiki editor (e.g. https://en.wikipedia.beta.wmflabs.org/w/index.php?title=Conflict-title-0.4322739948218497-I%C3%B1t%C3%ABrn%C3%A2ti%C3%B4n%C3%A0liz%C3%A6ti%C3%B8n&action=edit)
2. Open the Insert link dialog
3. Enter a full URL of a page on the same wiki you are editing (e.g. https://en.wikipedia.beta.wmflabs.org/wiki/Selenium_Echo_link_test_0.8604015944829051_0.8604015944829051)
   • it is at this point you will see the search dropdown appear
4. Click "Insert link"
5. Another dialog will pop up, click "Internal link"
6. Click "Insert link"
7. Keep repeating steps 2 to 6

Expected behavior: The outcome should be the same each time.
Observed behavior: Normally the 3rd time you attempt to do this the search dropdown will appear incorrectly (or won't appear at all if it is completely covered)

Repro two:

1. Open the 2010 wiki editor (e.g. https://en.wikipedia.beta.wmflabs.org/w/index.php?title=Conflict-title-0.4322739948218497-I%C3%B1t%C3%ABrn%C3%A2ti%C3%B4n%C3%A0liz%C3%A6ti%C3%B8n&action=edit)
2. Open the Insert link dialog
3. Enter a full URL of a page on the same wiki you are editing (e.g. https://en.wikipedia.beta.wmflabs.org/wiki/Selenium_Echo_link_test_0.8604015944829051_0.8604015944829051)
   • it is at this point you will see the search dropdown appear
4. Click "Insert link"
5. Another dialog will pop up, click "External link"
6. Keep repeating steps 2 to 5

Expected behavior: The outcome should be the same each time.
Observed behavior: Normally the 5th time you attempt to do this the search dropdown will appear incorrectly (or won't appear at all if it is completely covered)

Environment

Browser: Firefox 78. Chromium 87.
Wiki(s): https://en.wikipedia.beta.wmflabs.org MediaWiki 1.38.0-alpha (4c5102c) 09:42, 9 December 2021. WikiEditor 0.5.3 (bdb4f1c) 07:23, 9 December 2021.
Editor, if applicable: 2010 WikiEditor

Screenshots (if applicable):