I have the same problem. my whole company has this issue. sometimes it's large files. but the file I'm trying to share right now it less than 1MB and it stalls for minutes copying to teams then I get the sorry, something went wrong error. My internet connection is stable at about 500Mbps up and down. a 1MB pdf should not be too large to send. restarting teams does nothing.
While I can easily email the file, that is not the point. teams is supposed to be a quick way to communicate.