If you can't access some channels and it says:
This channel can not be displayed because it used to spread XXX content
You need to
disable sensitive content filtering in your account settings
on web version of Telegram
or PC application1. Open your browser (Google Chrome, Safari, etc)
2. Go to
web.telegram.org and login into your account
3. Open Settings -> Privacy and Security
4. Scroll down to Sensitive Content and check "Disable filtering"
5. Close your browser and restart Telegram application
Here is the video guide for that:https://www.youtube.com/watch?v=CoJO7rp2Lnk