So far it seems to work fine for me too. Can you share you list of security/privacy addons? I've used Umatrix but never heard of LocalCDN. Was wondering what other gems you may have found.
Here is a complete list of security/privacy addons I am using, a small number of which I have disabled, as I regularly toggle them depending on what I am doing at the time
AdNauseam
Archive Page
ClearURLs
Cookie AutoDelete
Cookie Remover
Decentraleyes
DoH Roll-Out
Don't track me Google
DuckDuckGo
Facebook Container
Firefox Multi-Account Containers
Firefox Private Network
Firefox Relay
Firefox Screenshots
First Party Isolation
Google Container
Google search link fix
Greasemonkey
HistoryBlock
HTTPS Everywhere
I don't care about cookies
Laboratory
Link Cleaner
LocalCDN
PinPatrol
Privacy Badger
Privacy Pass
Redirect AMP to HTML
Skip Redirect
Tampermonkey
Temporary Containers
Trocker
Twitter Container
uBlock Origin
Ugly Email
uMatrix
Wappalyzer
Zoom Redirector