AMAZON VPS NOT CORRECTLY CONNECTING

Hello, i am trying a free version of the amazon vps For the first 2 days it worked, even if quite slow, now it's 2 days that i am trying to connect with my remote connection but it's not possible, it gives me everytime error and it's impossibile to connect. The istance is working and there are not errors, however even if it's correctly working, i can't connect and i can't log in into the remote pc. How could i solve it? i already watched the youtube solutions but nothing solved my problem thanks in advance to whoever could help me