Random Highlighting

### Apache NetBeans version

Apache NetBeans 27

### What happened

Open two tabs containing code. Click on an item in one tab to highlight it, switch to the next tab and the highlight bleeds through. The more tabs open with items highlighted, the worse it becomes. See attached image:

### Language / Project Type / NetBeans Component

PHP

### How to reproduce

Open two tabs containing code.
Click on a key word in the first tab to highlight it.
Switch to the next tab and the highlight bleeds through.

### Did this work correctly in an earlier version?

Apache NetBeans 24 or earlier

### Operating System

Linux Mint 22.2 Zara base: Ubuntu 24.04 noble

### JDK

Java: 24.0.2; OpenJDK 64-Bit Server VM 24.0.2+12 Runtime: OpenJDK Runtime Environment 24.0.2+12

### Apache NetBeans packaging

Apache NetBeans binary zip, FoAN provided installer

### Anything else

I upgraded from Netbeans 24 to Netbean27. I don't remember Netbeans 24 having this problem

### Are you willing to submit a pull request?

No

Reproduce the highlighting bleed-through in Apache NetBeans 27 using two PHP editor tabs, then compare the behavior with NetBeans 24 or earlier. Trace the editor's per-tab highlighting behavior; done means selecting an item in one tab does not highlight it in another tab.

Written by the indexing model from the issue text.