I can't log in to the server and it shows me the start sign and it won't let me in??

If I try to enter the server, it loads cars for me, then tells me to start and it doesn’t let me in. Sometimes it lets me in, and I don’t know what the solution is. My friends and I are suffering from this problem. I hope for a response as soon as possible.

Could you send a screenshot of your BeamMP launcher?