Highlighting text appears to unhighlighted when tooltip/pop up appear

Does this issue occur when all extensions are disabled?: **Yes**

# Summary

While dragging to select text, a hover popup appears over the selection. The instant it does, the selected text stops looking selected. The highlight fades to a shade almost identical to the editor background, so it reads as though the selection was lost.

## Screenshots

With extensions disabled, this is JS. Notice how the function `log()` doesn't look highlighted anymore.

Here is a very pronounced .gif of the issue.

## System info

- VS Code Version: `1.135.0` (also observed on `1.113.0`)
- OS Version: `Linux amdx4 6.12.101+deb13-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.101-1 (2026-08-05) x86_64 GNU/Linux`

Steps to Reproduce:

1. Hover over text of function
2. Begin highlighting

**Actual Behavior**: Text loses highlight appearance and appears to be deselected

**Expected Behavior**: highlight text looks highlighted no matter what on-hover pop ups occur