How to fix Firefox asking for authentication again and again when connecting a proxy?

Question

proxy

I connected a proxy to Firefox, I used to change the proxy many times, they asked for a login, password and that's it. Now (I didn’t change anything in the settings) they ask for a login and password 10-30 times, and only then they load the site, and sometimes they ask again to enter them and click OK. Already pointed out:
network.automatic-ntlm-auth.allow-proxies = false
network.proxy.share_proxy_settings = false
network.negotiate-auth.allow-proxies = false
Nothing works. How to remove this bug? So that, as before, they asked 1 time and that's it.

Answer 1

use a local proxy server intermediary (redirect proxy)
3proxy