I cannot join my server sometimes

I have a problem with my server, I sometimes cannot join my server and it gets stuck at encrypting, and sometimes it works fine. When I start my server and I connect, then when I stop the server/the server stops, and I start it again, I cannot connect to it, even if I start it immediately, it still does not connect. How do I fix this problem?

By the way here is the log:

I noticed this happens mostly during afternoon CET and on weekends. Is it due to the time, the server or both?

Why is no one responding? I gave an in-depth detail of my problems.