Syntax highlighting is buggy in class folders

Describe the bug
When having code in a class folder (beginning with '@') the highlighting is inconsistent and all over the place for the main class declaration file. This reaches from just missing keyword highlighting (for, classdef, ...) to arbitrary words having multiple colors. This makes reading of documents very hard and efficient working nearly impossible.

To Reproduce
Steps to reproduce the behavior:

1. Create a class-folder (also nested in namespaces)
2. Create the classes main file, e.g. +mynamespace/@MyClass/MyClass.m
3. Create another method for the class and to arbitrary work on the class
4. open and edit documents. Sometime the behavior appears only after a loaded document is changed.
5. Visually inspect the document in VSCode.

Expected behavior
The same highlighting behavior between files in "normal" folders as in class folders.

Screenshots

Useful Information

• MATLAB Version: R2025b, 1.3.13
• OS Version: Ubuntu 24.04, Arch
• VS Code Version: 1.130

No source file or test is named. Start by reproducing the issue in VS Code with the nested MATLAB class-folder path +mynamespace/@MyClass/MyClass.m, including a method file and a changed loaded document. Compare highlighting with an equivalent normal folder; done means keywords and arbitrary words are highlighted consistently in the class-folder files.