WordPress Umlaute falsch dargestellt

Hallo liebes Support Team,

ich hab ein neu aufgetauchtes Problem mit den Umlauten.
Jeder neuer Text, welcher von mir mit dem Gutenberg Editor eingefügt wird verändert die Umlaute.
Aufgefallen ist mir auch, das dies scheinbar am liebsten in Spalten vorkommt:

https://famtain.webaddiction.de/memberships/

Leider hab ich in den alten Beiträgen keine Lösung für den Fehler finden können und wende mich jetzt an euch.

Hier der Bericht aus Website-Zustand:

### wp-core ###

version: 5.8.2
site_language: de_DE
user_language: de_DE
permalink: /%postname%/
https_status: true
user_registration: 0
default_comment_status: open
multisite: false
user_count: 1
dotorg_communication: true

### wp-paths-sizes ###

wordpress_path: /homepages/33/d867266687/htdocs/clickandbuilds/Famtain
wordpress_size: 763,62 MB (800716666 bytes)
uploads_path: /homepages/33/d867266687/htdocs/clickandbuilds/Famtain/wp-content/uploads
uploads_size: 14,26 MB (14956948 bytes)
themes_path: /homepages/33/d867266687/htdocs/clickandbuilds/Famtain/wp-content/themes
themes_size: 29,49 MB (30919231 bytes)
plugins_path: /homepages/33/d867266687/htdocs/clickandbuilds/Famtain/wp-content/plugins
plugins_size: 97,28 MB (102009261 bytes)
database_size: 41,95 MB (43991040 bytes)
total_size: 946,61 MB (992593146 bytes)

### wp-active-theme ###

name: Astra (astra)
version: 3.7.5
author: Brainstorm Force
author_website: https://wpastra.com/about/?utm_source=theme_preview&utm_medium=author_link&utm_campaign=astra_theme
parent_theme: none
theme_features: core-block-patterns, astra_hooks, widgets-block-editor, align-wide, automatic-feed-links, title-tag, post-thumbnails, html5, post-formats, custom-logo, customize-selective-refresh-widgets, editor-style, woocommerce, rank-math-breadcrumbs, amp, widgets, menus
theme_path: /homepages/33/d867266687/htdocs/clickandbuilds/Famtain/wp-content/themes/astra

### wp-themes-inactive (2) ###

Twenty Nineteen: version: 2.1, author: WordPress-Team
Twenty Twenty: version: 1.8, author: WordPress-Team

### wp-mu-plugins (3) ###

1&1 Product Subdomain: version: 1.1.0, author: 1&1
Health Check Troubleshooting Mode: author: (undefined), version: 1.7.2
ManageWP - Worker Loader: version: 1.0.0, author: GoDaddy

### wp-plugins-active (15) ###

All-in-One WP Migration: version: 7.50, author: ServMask
Astra Pro: version: 3.6.3, author: Brainstorm Force
Autoptimize: version: 2.9.3, author: Frank Goossens (futtta)
Complianz | GDPR/CCPA Cookie Consent: version: 5.5.2, author: Really Simple Plugins
Contact Form 7: version: 5.5.3, author: Takayuki Miyoshi
Custom Fonts: version: 1.3.3, author: Brainstorm Force
Editor Plus by Extendify: version: 2.9.3, author: Extendify
EWWW Image Optimizer: version: 6.3.0, author: Exactly WWW
Getwid: version: 1.7.7, author: MotoPress
Health Check & Troubleshooting: version: 1.4.5, author: The WordPress.org community
Honeypot for Contact Form 7: version: 2.1, author: Nocean
ManageWP - Worker: version: 4.9.10, author: GoDaddy
Rank Math SEO: version: 1.0.77.1, author: Rank Math
Ultimate Addons for Gutenberg: version: 1.25.2, author: Brainstorm Force
Yoast Duplicate Post: version: 4.2, author: Enrico Battocchi & Team Yoast

### wp-plugins-inactive (1) ###

UpdraftPlus - Backup/Restore: version: 1.16.66, author: UpdraftPlus.Com, DavidAnderson

### wp-media ###

image_editor: EWWWIO_GD_Editor
imagick_module_version: Nicht verfügbar
imagemagick_version: Nicht verfügbar
gd_version: 2.2.5
ghostscript_version: 9.27

### wp-server ###

server_architecture: Linux 4.4.284-icpu-077 x86_64
httpd_software: Apache
php_version: 7.4.25 64bit
php_sapi: cgi-fcgi
max_input_variables: 1000
time_limit: 30
memory_limit: 1024M
max_input_time: -1
upload_max_size: 128M
php_post_max_size: 128M
curl_version: 7.64.0 OpenSSL/1.1.1d
suhosin: false
imagick_availability: false
server-headers: 
	content-type: text/html; charset=UTF-8
	date: Thu, 02 Dec 2021 12:38:24 GMT
	server: Apache
	x-powered-by: PHP/7.4.25
	expires: Wed, 11 Jan 1984 05:00:00 GMT
	cache-control: no-cache, must-revalidate, max-age=0
	link: <https://famtain.webaddiction.de/wp-json/>; rel="https://api.w.org/", <https://famtain.webaddiction.de/wp-json/wp/v2/pages/10>; rel="alternate"; type="application/json", <https://famtain.webaddiction.de/>; rel=shortlink
	content-encoding: gzip
htaccess_extra_rules: true

### wp-database ###

extension: mysqli
server_version: 5.7.33-log
client_version: mysqlnd 7.4.25

### wp-constants ###

WP_HOME: undefined
WP_SITEURL: undefined
WP_CONTENT_DIR: /homepages/33/d867266687/htdocs/clickandbuilds/Famtain/wp-content
WP_PLUGIN_DIR: /homepages/33/d867266687/htdocs/clickandbuilds/Famtain/wp-content/plugins
WP_MAX_MEMORY_LIMIT: 1024M
WP_DEBUG: false
WP_DEBUG_DISPLAY: true
WP_DEBUG_LOG: false
SCRIPT_DEBUG: false
WP_CACHE: false
CONCATENATE_SCRIPTS: undefined
COMPRESS_SCRIPTS: undefined
COMPRESS_CSS: undefined
WP_LOCAL_DEV: undefined

### wp-filesystem ###

wordpress: writable
wp-content: writable
uploads: writable
plugins: writable
themes: writable
mu-plugins: writable

Tausend Dank!

Julie

Die Seite, für die ich Hilfe brauche: [Anmelden, um den Link zu sehen]