i'm a total newbie to rewrite and redirect rules and i have some strange problems on my multisite.

when i try to open www.my-website/blog or www.my-website/xmas for example, in safari browser everything works fine.

when i try to open that link in chrome or firefox i'll end up on the start page. but if i'm on the start page an try to open the link a second time, everything is doin well.

<IfModule mod_headers.c>

RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
</IfModule>
<IfModule mod_rewrite.c>

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteRule ^presse/ / [R=301,L]
RewriteRule ^kompetenzen/Gesundheitsmarketing.html / [R=301,L]
RewriteRule ^kompetenzen/ / [R=301,L]
RewriteRule ^news/ / [R=301,L]
RewriteRule ^shared/ / [R=301,L]
RewriteRule ^ueber_uns/ / [R=301,L]
Redirect 301 /de /
Redirect 301 /impressum.html /
Redirect 301 /karriere/index.html /
Redirect 301 /leistungen/Promotion_Personalgestuetzte_Verkaufsfoerderung.html /
Redirect 301 /?author /

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
RewriteRule . index.php [L] 

like i said, i'm a total newbie to htaccess stuff.

i hope someone can help me.

thank u very much :)

EDIT: i forgot the security headers

# Security Headers
<IfModule mod_headers.c>
    Header set X-XSS-Protection "1; mode=block"
    Header set X-Frame-Options "SAMEORIGIN"
    Header set X-Content-Type-Options nosniff
    Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains"
    Header set Content-Security-Policy "frame-ancestors 'self';"
    Header set Referrer-Policy "same-origin"
    Header set Feature-Policy "geolocation 'self'; vibrate 'none'"
</IfModule>