You can try the following steps to solve this problem.
1. If you are using a PC, then you can boost the Optional server in Easy Lobby.
2. If you are using a Console, then you can search for Easy Lobby Optional Server and boost it.
3. If you can't solve this problem even after using Optional server, then we suggest you to check if you are shadow banned according to the following faq
https://www.lagofast.com/en/support/29