List of steps to reproduce
I have a table:

{| class="plainlinks"
|- valign="top"
| style="width:50%" |
...
|
...
|}

What happens?:

When saving the text from the Visual Editor the following line is not stored:

|- valign="top"

Table is stored as:

{| class="plainlinks"
|-
| style="width:50%" |
...
|
...
|}

Result:

1. the table row is not aligned at the top...
2. I need to edit the page again with the Tag editor and add the line valign="top" again

What should have happened instead?:

The valign="top" option should be stored with the top row of the table.

Software version (if not a Wikimedia wiki), browser information, screenshots, other information, etc.:

MediaWiki 1.39.0-wmf.7 (800f261)
12 apr 2022 02:08