Since 24th August, there were ongoing attacks on most of large servers in Hosted and Internet tab in game client. The attackers flooded servers with large amount of packets, which resulted in servers not being displayed properly in game client - it didn't load instantly server name, amount of players nor ping - and it could take a while before all data were loaded. This issue also caused, that not all servers were displayed in Hosted and Internet tab.
Currently, Kalcor, the SA-MP developer, released new version of server, which should minimize the impact of the attacks and servers using the latest version should be working properly, even when still under attack - and most of the servers still are under attack. Kalcor also stated his suspicion, that it's spanish roleplay servers from South America, who is behind these attacks and they were using servers from hosting company OVH in Canada, which they used to send packets with spoofed IP addresses and flooded other servers with them.
Everything should work properly now and it's good to know, that even though Kalcor was inactive on SA-MP forums nearly for a year and already over two years passed since last SA-MP version release, Kalcor still cares for SA-MP and there is still chance that we will see some updates for SA-MP in the future!
I Hope SAMP can survive for next few decades to come.