Error When Hiding Backend Menu Items

I have created a custom role and am attempting to edit the backend menu to hide certain items. It makes no difference whether the menu items come from plugins or are core WordPress items — some of them I was able to hide successfully, while others trigger an error.

When the issue occurs, I receive the following error message:

“An unexpected application issue has arisen. Please feel free to report this issue to us, and we will promptly provide you with a solution.”

Additionally, the loading icon next to the checkbox keeps spinning indefinitely, and the item cannot be hidden.

Upon further inspection, I noticed that a 403 error appears in the browser console at the moment the issue occurs. The request URL that fails is:

https://xxx/wp-json/aam/v2/backend-menu/ZWRpdC10YWdzLnBocD90YXhvbm9teT1jYXRlZ29yeQ==?access_level=role&role_id=c-editor

This behavior occurs consistently and appears to affect both core and plugin-generated menu entries.

I am attaching additional information about the website for your reference.

Steps to reproduce:

1. Create a custom role, duplicate standard editor (e.g. c-editor).
2. Open the backend menu editor.
3. Try to hide various menu items.
4. For some items, observe the 403 error and the infinite loading spinner.

### wp-core ###

version: 6.8.2
site_language: de_DE
user_language: de_DE
timezone: Europe/Berlin
permalink: /%category%/%postname%/
https_status: true
multisite: false
user_registration: 0
blog_public: 1
default_comment_status: undefined
environment_type: production
user_count: 2
dotorg_communication: true

### wp-paths-sizes ###

xxx

### wp-active-theme ###

xxx

### wp-themes-inactive (1) ###

Twenty Twenty-Five: version: 1.3, author: Das WordPress-Team, Automatische Aktualisierungen deaktiviert

### wp-mu-plugins (1) ###

aios-firewall-loader.php: author: (undefined), version: (undefined)

### wp-plugins-active (31) ###

Advanced Access Manager: version: 7.0.8, author: VasylTech LLC <[email protected]>, Automatische Aktualisierungen deaktiviert
Advanced Custom Fields PRO: version: 6.5.0.1, author: WP Engine, Automatische Aktualisierungen deaktiviert
All-In-One Security (AIOS): version: 5.4.2, author: TeamUpdraft, DavidAnderson, Automatische Aktualisierungen deaktiviert
Block Visibility: version: 3.7.1, author: Nick Diego, Automatische Aktualisierungen deaktiviert
Clean Image Filenames: version: 1.5, author: Upperdog, Automatische Aktualisierungen deaktiviert
CMS Tree Page View: version: 1.6.8, author: Jon Christopher, Automatische Aktualisierungen aktiviert
Conditional Fields PRO: version: 2.6.3, author: Jules Colle, Automatische Aktualisierungen deaktiviert
Contact Form 7: version: 6.1.1, author: Takayuki Miyoshi, Automatische Aktualisierungen deaktiviert
Contact Form 7 Apps: version: 3.0.0, author: CF7Apps, Automatische Aktualisierungen deaktiviert
Download Monitor: version: 5.0.33, author: WPChill, Automatische Aktualisierungen deaktiviert
Duplicator Pro: version: 4.5.22.4, author: Duplicator, Automatische Aktualisierungen deaktiviert
Enable Media Replace: version: 4.1.6, author: ShortPixel, Automatische Aktualisierungen deaktiviert
EWWW Image Optimizer: version: 8.2.0, author: Exactly WWW, Automatische Aktualisierungen deaktiviert
FluentSMTP: version: 2.2.90, author: FluentSMTP & WPManageNinja Team, Automatische Aktualisierungen deaktiviert
Make Tables Responsive: version: 1.8.0, author: Nikolay Nikolov, Automatische Aktualisierungen deaktiviert
Matomo Analytics - Ethical Stats. Powerful Insights.: version: 5.3.1, author: Matomo, Automatische Aktualisierungen deaktiviert
Media Focus Point: version: 2.0.1, author: WP Company, Automatische Aktualisierungen deaktiviert
PublishPress Future: version: 4.8.2, author: PublishPress, Automatische Aktualisierungen deaktiviert
Rank Math SEO: version: 1.0.251.1, author: Rank Math SEO, Automatische Aktualisierungen deaktiviert
Real Cookie Banner: version: 5.1.19, author: devowl.io, Automatische Aktualisierungen aktiviert
Real Media Library: version: 4.22.47, author: devowl.io, Automatische Aktualisierungen aktiviert
Relevanssi Premium: version: 2.27.7, author: Mikko Saari, Automatische Aktualisierungen deaktiviert
Simple History: version: 5.15.0, author: Pär Thernström, Automatische Aktualisierungen deaktiviert
WP Fastest Cache: version: 1.3.9, author: Emre Vona, Automatische Aktualisierungen deaktiviert

### wp-server ###

server_architecture: Darwin 24.5.0 arm64
httpd_software: Apache/2.4.62 (Unix) mod_wsgi/5.0.1 Python/3.12 mod_fastcgi/mod_fastcgi-SNAP-0910052141 OpenSSL/1.1.1w
php_version: 8.4.10 64bit
php_sapi: cgi-fcgi
max_input_variables: 1000
time_limit: 30
memory_limit: 128M
admin_memory_limit: 256M
max_input_time: 60
upload_max_filesize: 32M
php_post_max_size: 8M
curl_version: 7.76.1 OpenSSL/1.1.1w
suhosin: false
imagick_availability: true
pretty_permalinks: true
htaccess_extra_rules: true
static_robotstxt_file: true
current: 2025-08-21T08:27:26+00:00
utc-time: Thursday, 21-Aug-25 08:27:26 UTC
server-time: 2025-08-21T10:27:24+02:00

### wp-database ###

extension: mysqli
server_version: 8.0.40
client_version: mysqlnd 8.4.10
max_allowed_packet: 268435456
max_connections: 151

### wp-filesystem ###

wordpress: writable
wp-content: writable
uploads: writable
plugins: writable
themes: writable
fonts: does not exist
mu-plugins: writable