I have installed proxybroker several times using different process pip etc. There were times it conflicted with other programs. There were times it would only work for US proxies. Finally I installed in a virtualenv using pip and the developmental version. It only scrapped US proxies. So I said to myself, "Self, I wonder what would happen if I started and EU based VPN?" So stopped the program, virtual environment, started a vpn in the Netherlands, restarted the virtualenv, and what happened? Proxybroker not only worked but scraped other countries as well. So the problems, for me, were tricky installation and possible mischief with my ISP.
All of this was done on Kali Linux 2023-2 live usb.