Playback problems

Hi everyone. I have encountered something strange and would be grateful for good advice.
I am using the latest version for Windows, I have my own podcast and I also teach kids in school how to make their own podcast. In one school the laptop should be connected to the screener in a wireless way via a certain software they use. I have connected to the screener when Audacity was open on my computer and ever since the playback doesn’t work properly. With the computer loudspeakers selected there is no sound. When I connect the audio mixer it does work for some reason. Tried to remove the other software and then also remove Audacity and download again and it didn’t work. I also looked at all the sound settings I could find on the computer, but still didn’t solve the problem.
If anyone had something similar or has an idea I would be more than happy to hear.
Thank you very much.