Pro licence + large meetings = the last meeting I hosted was a disaster please help!

hi everyoone, I have the pro licence and I also purchased lasrge meetings feature to host a training for 150+ people. It started fine but after 5-10 min the participants said my screen froze. Then I was cut out a twice and zoom assigned somebody else as host. The connection was secure however we couldnt continue. Some of the participants couldnt join the meeting either. I wrote to help desk no answer and my next meeting is on monday