I’ve never had this issue until I recently had to re-establish my plex server for some reason. I have the plex app on all of my TV’s and for some reason, the server is not available on the TV unless I keep my macbook pro turned “ON”. Once I open the laptop, the connection comes back. However, if i simply close the lid of the laptop, server gets disconnected on all TVs. Please help.
Plex Media Player requires the server to be present on your network. I assume the server is on your MacBook Pro so when you close the lid your macbook goes to sleep.
You may not have had this before (or had catalina installed on your macbook) meaning your macbook goes to sleep immediately instead of entering clamshell mode.
As SE56 said best is to change your power settings and go from there.