Problem

When using a Japanese IME, the first character of input is automatically confirmed if the input begins immediately after a whole line, heading, or table cell is selected. This behavior is intermittent and has been difficult to consistently reproduce in our internal environment, but the customer has confirmed it occurs consistently for them.

Environment

Confluence cloud

Steps to Reproduce

1. Open a Confluence page with a table or heading.
2. Perform one of the following actions to select a whole line of text:

• Click and drag the mouse to select an entire line.
• Press the *Tab key* inside a table cell that contains a value. This action automatically selects the contents of the next cell.
  3. Immediately begin typing a word using a Japanese IME (e.g., type "konnnitiha").

Expected Results

The full word "こんにちは" is entered without the first character being prematurely confirmed.

Actual Results

The first character ("k") is confirmed, and the rest of the input follows it, resulting in a typo like "kおんにちは".

Workaround

Users can delete the incorrect, partially confirmed text and re-type the word.

Notes

• Intermittent Reproduction: The bug is not 100% reproducible in our internal testing environment, occurring only intermittently.
• The issue has been confirmed to occur in multiple browsers (e.g., in incognito mode).
• The issue affects multiple users on the same site.
• This bug appears to be triggered by the "whole line selection" state, which is automatically activated after a Tab key press in a table.