This article covers just the Meet-specific issues, so if you haven't already reviewed Why didn't Read join my meeting? you are strongly encouraged to do so.
If you have Read configured to join your Google Meet calls, but you're not seeing it join or even try to join when you get on the call, you may not have permission to allow Read (an uninvited guest) to join the meeting. In this case, you should see the meeting listed on your Incomplete reports page with the message "Read not admitted to the meeting within 10 minutes of scheduled start time."
Whether Read requires permission to join or not depends on who created the meeting. If the Meet creator is on a personal @gmail.com account, they are the only one who can admit uninvited guests (i.e. Read) to the call. If the Meet creator belongs to a Google Workspace (has a work or school Google account), then their Google Workspace settings will determine whether Read can join on its own or whether it needs to ask to be admitted.
Only Google Workspace admins can view and change this setting, but you can read Google's instructions here: https://support.google.com/a/answer/13722774?hl=en
Unless the meeting access type is set to "Open", Read will need to be admitted by someone in the same Google Workspace as the meeting creator. If you join a meeting hosted by someone from another organization, there is a good chance that only people from that organization will be able to see and approve of Read's request to join the meeting.